London Pass--book ahead or no?

I've used the London Pass at both of those places and neither place requires any advance reservations. That said, those are two locations where I make a point of being there when they first open to reduce the crowds that I am dealing with. It took me all of 60 seconds to show my pass and get into the Tower of London. Probably 4 minutes in line at Westminster Abbey.
(Make sure to sign up for a Verger tour as soon as you enter and pay the extra. It is worth it.) Have a great trip.

Their website has the very short list of places that need to be booked - most of these are the less known sites. For the very popular you walk up and say you have the pass - you might need to wait for the next opening slot, but it's never long

For most visitors the London Pass is very poor value, so you need to check that the sights you want to see are available on the pass and that you can sensibly see them properly in the time you have available. For example a HoHo bus service is usually included but most locals would recommend that you don't do it because of the interminable traffic in central London.
Bear in mind that many sights are free to enter (most museums and galleries). You also cannot bypass the security queue with a pass or an ordinary advance ticket.

In most cities I tend to think that the tourist pass represents poor value.

Just as an example I was looking at the Uber Boats option last night. It says that the day pass is £23, it is if purchased at the pier, but in fact it is £2 less if purchased on line. It also fails to mention that there is a much cheaper option purely for central London, if you don't want to go out east, which probably is all many visitors want.
It also does not appear to give senior discounts- which many attractions do when booked direct.
There are several companies operate HoHo buses (if you do want to do that)- the London pass ties you to one.
I think their wording about the Visitor Oyster Card sails close to the wind. It at least strongly implies that the £50 credit for a week covers all 9 zones, and is all you need. I thought that was great value, but it's not, it's credit, not unlimited travel. But I had to read the TfL website to be sure of the meaning. If I have to do that, then it really is not as clear as it could be.

I just wonder how many other not quite correct statements the website makes.

I don't doubt that the pass makes financial sense for some people, but you have to do your math carefully and check each attraction's prices to see if it is really worth it for you.

Caveat Emptor as they say.

At the end of the day it is a profit making company, not a Charity.

The many magnificent, large, free/donation-requested museums in London make it far less likely a first-time visitor will benefit financially from that pass. I wonder how many travelers end up going to enough pass sights even to break even. London is large, so it's likely considerable time will be spent just moving from place to place, and that will cut into time available to spend actually at sights.

Although there are some important sights covered by the pass (including the Tower of London, Westminster Abbey, St. Paul's Cathedral), the list is padded with an awful lot of places short-term visitors would probably (and rightly) ignore. How many of the other sights would the typical visitor prioritize over the (free/donation-requested) British Museum, for example?

Colleen, have you already purchased the pass? If not, I encourage you to think twice before buying it.
You wrote:
"According to the London Pass information, Pass customers do not need to book ahead."
"Pass customers do not need to book Tower of London tickets in advance but please be aware that at busy times, you may be asked to wait for the next available time slot."

I would encourage you to compare the information you are getting from the pass website with the information provided on the Tower of London website:
https://www.hrp.org.uk/tower-of-london/#gs.ue0yun
Tower ticket prices here:
Adult: £29.90
Nowhere does it say you MUST buy tickets in advance. I would just be there at the gate right before 9 AM, purchase a ticket and walk right in. We were able to walk right in at this time of the day. If you wish to purchase tickets from their website online, it is easy to do.
Opening time 9 AM.

Tower of London costs..........£29.90.
Westminster Abbey costs......£27.00.
Total.............................................£56.90.

A one-day London Pass costs £84.00 for an adult.

Are you saying that if you only want to visit Tower of London and Westminster Abbey in one day, you'd rather pay £84.00 to have the London Pass as opposed to just walking up and paying £56.90 to see the two sights?

The fact that the London Pass boasts it covers "90 attractions" does you no good, because you cannot see 90 attractions in one day, or even in 2 or 3 days, if you buy the much more expensive passes.

The most you might be able to see and enjoy would be Tower of London in the morning, up until lunchtime, and then Westminster Abbey, entering about 2 PM.

You might have time for one more sight using the one day London Pass; then you might be just "breaking even" on the cost of the pass.

We have looked at the London Pass before, added up the attractions we wanted to see, and discovered it's not a good value for us because of the limited time you have to see the things on the list it covers.
For us, using the London Pass would have been more of a hassle than a benefit.

Check twice to make sure you aren't actually paying MORE to use the pass than you would by buying tickets on your own.

Plus, the museums in London are free anyway. We spend a lot of time at the British Museum (free).

Westminster Abbey is free if you go there for a service. You wouldn't be able to walk around to every nook and cranny then, but you'd get a good look at the inside, plus hearing some lovely music.

I knew that people just couldn’t help themselves…….

Yep. Hate to see people waste money. And possibly run themselves ragged trying to make a pass pay off--possibly missing some of the city's most interesting sights in the process since they're free/donation-requested and therefore not covered by the pass.

Here is the thing. I am going to respect that the person asking the question did their research and made the decision that he/she felt was right for that trip, that itinerary. I’ve been to London 4 times. Each time I priced out the itinerary and admissions for my plan. 2 times the London Pass made sense and I purchased it . Two times it would not have done so and I did not.

I think that sometimes we ( and I include myself in that we) can be a little too fast to assume others need our opinions about every aspect of their trip. Sometimes, they just need a question answered.

I'd have answered the question Colleen posed if I could have.

I have a different take on situations like this. Sometimes travelers assume a travel product is a good deal because it is being offered. (Refer to the many posts about Eurail passes.) That is not always the case. In addition, although Colleen may well have done the research, made the right decision and already purchased the pass (although the post does not indicate that she has the pass at this point), others may encounter this thread later, and if no one says anything about the very problematic nature of this particular sightseeing pass, might they not assume it is a good thing for them?

We've had plenty of threads here started by travelers who had made an assumption about the utility of some sort of pass (but hadn't yet purchased it). Some of them subsequently changed their minds after reading the responses they received.

I wouldn't be surprised if some repeat visitors benefitted from a city pass that would be highly questionable for a first-timer. Repeat visitors may be going back to places they've seen before just to see their favorite exhibits and/or they may be visiting smaller sights and therefore going to more places each day. They are probably able to move around the city faster than a first-time visitor.

"I knew that people just couldn’t help themselves……. "
Carol, your opinion is respected and valued here,
but so are the opinions of the other posters on this thread.

I don't see how anyone could object to me doing a cost comparison of doing Tower of London and Westminster Abbey buying one's own tickets, versus the cost of buying the pass in order to do them.
Unless that person was working for the London Pass promoting it here; then they might object.

acraven, your posts raise excellent points. One would have to run all over London like a mad person to make the pass pay off to the max. Your other post up the thread mentioning all the excellent free museums certainly made the point that one can see many of the most important sights without any pass aimed at tourists.
British Museum,
Museum of London,
The Tate,
Tate Modern,
National Gallery,
National Portrait Gallery,
The Victoria and Albert Museum,
Science Museum,
Natural History Museum, and more.......
for free and need no pass to get in.

There are "newby" visitors to London (and to this website) that do not know these museums are free.

acraven, you are right also about the first-time visitors to Europe who think they must buy Eurail passes just because they've heard of them.

I personally thought that my response was measured and reasonable in that I specifically said that it may suit some people but not others. As a British citizen I had not actually heard of this pass, so was quite interested to see what it was and what it included.
To me some of the lesser known attractions and museums included were interesting in their own right, although like others am not sure how many visitors (even repeat visitors) would go to those.
I brought up two specific issues which leapt off the page at me, but visitors may not be so aware of.
As such I consider that I was being a responsible respondent.
I am also aware that these threads are a reference source to people, although I wasn't aware until today that they link through to relevant RS tour pages, which increases their reference utility (I think it was one of acravens posts on another topic which told me that).
Thus we had a thread over the weekend about Rievaulx Abbey. I added to that thread more general local detail, not because it was needed by the OP but anyone else looking at that thread would find useful relevant detail which may be beneficial to such future readers.
Yes I went beyond the call, but was bending over backwards to be productively helpful and thoughtful.
Everyone has a different travel style, this type of pass suits some people's travel style, but not others.
I know I have a very quirky travel style for instance.
I fully respect that it has paid off for carol now retired a couple of times.
It's the same way as a Seattle City Pass would never pay for my travel style and interests, but I have no doubt does so for many people, and yes I have looked closely at that one.

isn31c, your post was perfectly reasonable.

Thank you for your many posts, in which you go well beyond the obvious "yes" or "no" to a poster, and give wonderful extra details. You should not be chastised by someone saying "Just answer the question as asked and shut up!" That is never a good thing. We had a guy on this forum like that a couple of years ago. Thought it was his biz to chastise people and tell them what they could and could not say. We all try to give the best information we can when someone asks a question here. It's up to the OP to take the advice or to ignore it. No one is harmed by the extra information (or opinions) given.
We all learn from all the extra information that members give when they get engrossed in a subject and mention side trips near an OP's planned destination, or recommendations for a good pub meal....on and on like that.

isn31c, I appreciate each and every post you've made on this forum. Thank you for spending your time here with us.

Thank you all for your help: for answering my question and providing additional information. Much appreciated!

I'd support Rebecca's comments about isn31c and his detailed and very helpful posts. His knowledge of bus and railway timetables never ceases to amaze me.