Compare these two itineraries - London....Amsterdam vs London...Prague

To compare and contrast as you ask, the obvious differences are distance and number of stops. All the destinations are worthwhile, of course (though "Germany" could be a lot of places). The first choice puts you on planes and trains for at least part of three days out of the seven you've allotted to the continent. So you have four non-travel days left for "Germany" and two big cities near Germany.

I loved Vienna and Prague but I wouldn't try to "see" them and anyplace in Germany in such a short time. I'd suggest you go with London-Belgium-Amsterdam. The Eurostar will take you from London to Brussels in about two hours. The Thalys will take you on to Amsterdam in about the same time. You could spend that week visiting Belgium (Brussels, Brugge, Ghent) and the Netherlands (Amsterdam, Haarlem, ??). If you haven't made your flight arrangements, you should try to fly "open jaw," into London and home from Amsterdam, to save travel time in Europe. This is the "multi-city" option on flight search engines like Kayak, and should save money as well as time.

If this were my trip and I hadn't been there before, I'd give London more time than your 3-4 working days, and focus on either Belgium or Netherlands for the last few days (or, really, stay in England if I hadn't been before). But you know where you want to go.

you could do either. I would maybe do the following.

London fly to Berlin (2) would have time the first day and then the next full day.

train to Prague (2) About a 5 hour trip
train to Vienna (2) About a 4 hour trip
You could then add one night or allow one day to get back to London.
This is quick and basically allows you one full day in each stop with moving every 2 days. I prefer not to move every day. Its a lot more work. The day you arrive if you leave in the morning would give you a 1/2 day more. Basically giving you 1 1/2 days for each stop and a little more in Berlin. I just picked Berlin because there is so much to see and do and its easy to connect then to Prague. Plus if London is 3 days instead of 4 you could add one more day and I would add it to Prague vs Vienna.

If you do the Netherland/Belgium option you would be less rushed. Could easily take trains and would have wiggle room.

thank you. Very helpful.

London-> Germany->Vienna-->Prague seems like it may be too rushed for only 10 total days...

Belgium and Amsterdam are closer to London and you can do it by train. Germany, Vienna, Prague. Germany is big, 7 days are too few, you don't want to cut Vienna or Prague so you will have to cut Germany. Then you would fly either to Vienna or Prague whatever deal is better for you. Connect between those two cities by train or Yellow Bus. The cheapest airfare from London is by Ryan Air (caution! They have many restriction, read about them). Ryan Air flies from London Stanstead to Brno which is half way between Prague and Vienna. If you can live with their restriction, the flight is ridiculously cheap.

London - Belgium - Amsterdam is the only reasonable option in the time you have. You have so few days, you should spend as little time on travel between destinations as possible. Even a two or three hour train ride involves time getting to the station, waiting, and getting from the next station to your hotel. I absolutely loved Belgium. From Brussels, you can do short and easy day trips to Brugges or Ghent. I haven't been to Amsterdam, but it is on my list.

Door 2.

The other one is a logistic mess that gobbles your little bit of time. Germany is kind of vague, anyway, but just one place would be a deal-breaker.

You didn't say when you are going, but be aware that the trains from London to Brussels and Brussels to Amsterdam use "airline pricing." This means they are affordable if bought in advance as non-refundable and non-exchangeable, and prices rise substantially if you wait; last minute tickets can be insanely expensive. So, book these train segments as soon as you know your plans and tickets are available for your dates.

London to Brussels is booked at http://www.eurostar.com; lots of tips at http://www.seat61.com/London-to-Paris-by-train.htm#.U1HYOFeZgVI. If you're going to a destination in Belgium besides Brussels, here's some tips: http://www.seat61.com/Belgium.htm#Other%20destinations%20in%20Belgium

Brussels to Amsterdam is booked at http://www.thalys.com; tips are at http://www.seat61.com/thalys.htm#.U1HZEleZgVI

Thanks. We are going Mid-may so we will start looking into buying tickets this weekend.

I assumed we didnt have enough time to properly do London->Berlin->Vienna->Prague and the responses confirmed it. One of my friends was insistent we try to do that, so i wanted to get other people's feedback.

thank you all!

Another way to get between London and Amsterdam is by Stena ferry. You can book a train-and-ferry package, including an overnight cabin to save time. I haven't done this but it might meet your needs if you'd rather spend time in Netherlands than Belgium.

A few possible things in short:
Open jaw from US: London - Amsterdam
Highspeed train London – Brussels some 2 hours
Additional train from latter to Ghent takes ½ hour
Base Ghent, train to Bruges ½ hour, total time from centre to centre is about 1 hour.
Intercity train Ghent to Antwerp 1 hour, quickest highspeed train further to Amsterdam 1¼ hour.
Amsterdam base for daytrips to Haarlem, Leiden, Utrecht etc.
If necessary budget or feeder flight back from Amsterdam to London