Luftansa or British Airways?

That depends on where I'm going. But in general my choice would be Lufthansa since that means I can avoid Heathrow.

What don't you like about Heathrow? Just curious.

I’ve been the recipient of a same day flight cancellation from Lufthansa due to a strike. It was not pleasant. I usually fly British Airways transatlantic because they are one world and partner with my Alaska Airlines frequent flyer account. I’ve been through Heathrow many times. It is big, lots of walking, but I don’t view it as a problem airport.

After using Lufthansa for many flights we have switched to Delta. But, we have taken BA and we had great flights with them. I would try to fly with them before Lufthansa. Sometimes you really don’t have a choice though.

I like BA because I like to just do a carryon and they have a higher weight limit than Lufthansa’s 17.6 lbs. (I fly economy).

I'd choose BA over Lufthansa. As mentioned, they are very lenient on carry on. Lufthansa, lately, has not been getting high marks for anything.

Thank you for your input! Any thoughts on KLM?

i would pick neither.
LH and BA are just as bad as each other.

Please choose Swiss.

It looks like you are taking your family to Germany next February. Is that correct? Where are you starting from? That may help narrow down the best airline choice. Ideally you want a direct flight from your home airport to an airport in Europe (Heathrow, Frankfurt, Paris, Amsterdam, etc.) to start. Then a short domestic flight to your destination (or maybe train if you fly into Frankfurt).

As for British Airways, we have flown them on almost every trip to Europe the past 20 years. We do not mind Heathrow and like BA. The only time we have not flown BA, because we ran out of miles, we flew Condor. They have direct flights into Frankfurt from a few US cities (including Seattle).

We are heading out from Boston and going to Berlin. So we would prefer our connection in Europe so we don't have the worry about potential snow delays. Thoughts on KLM?

LHR is a nightmare zoo. That being said I find the cheapest one stop flight on Google Flights, then check it with the airline site and if it's still the cheapest and if the layovers are 2 to 4 hours, I book it. Doing that over the years has probably saved enough for 25% more travel to Europe. I can survive any airline, I just want to travel more.

Regarding KLM-I've flown with them from Amsterdam to our final destination in Europe a number of times, including Berlin. Always connecting to/from a US Delta flight. Nothing fancy, but I've never had an issue and usually depart/arrive within an hour of the schedule.

Are you looking to fly Delta from Boston to Amsterdam, then onward to Berlin? I like that my Delta flights from the West Coast arrive early enough that, should there be a delay, there are later onward flights to connect with.

I do not see any KLM flights out of Boston. They put you on either Delta or Air France for the longhaul flight, connecting with a KLM Air France flight to Berlin, at either Paris or Amsterdam.

From what I have read, CDG is a nightmare (which is even worse than a zoo), so I would choose the Delta flight and connect in Amsterdam to KLM.

Looks like the roundtrip on Delta is as low as $815 in February if you choose the lowest Economy fare (hand baggage only, etc). Compare that price to what it costs if you book on the Delta site.

To be honest they are much of a muchness -- delays can happen outside an airline's control, baggage gets lost and customer service staff are overwhelmed at times.

Think about, duration, price and convenience. Convenience means where you might transit - if on BA then you will avoid immigration at LHR and do it at Berlin. If both legs are on BA then you do all that within Terminal 5 so it's not bad. If with KLM you do immigration in Amsterdam - again another convenient terminal change then onward to Berlin.

What fare class - if it's business or first then you'll get all your needs catered for. If economy - well it's just getting there in one piece really.

Is there any benefit or hindrance to buying your ticket through a travel agent as opposed to booking with the airline direct?

What don't you like about Heathrow?

It's huge and a bit chaotic. It also operates at very close to max capacity to small delays can easily become huge delays. Also you always have to go through a security check at Heathrow.

KLM is not a terrible option. And if you're travelling from Boston to Berlin you can also have a look at SAS via Copenhagen, a very easy airport for transfer.

Is there any benefit or hindrance to buying your ticket through a
travel agent as opposed to booking with the airline direct?

The better question is: Is there any benefit to buying your ticke through a travel agent?

No, not that I can think of. The downside might be that if there is any problem you might have to deal through the travel agent. Dealing with the airline direct is much easier. You also get to review the terms of the various fares in detail and make the best decision for you. Yes, you can do that with an agent, but again, its a middle man that really provides little or no value these days.

Go to google flights, pick maybe three flights that have good prices and schedules then visit the airline sites and check them. The Basic economy on one airline may work well for you, but on another the restrictions may be too great even if the ticket is cheaper. Same if you are traveling in a higher class. Each airline has their own rules and limitations and sometimes perks. So you have to do some shopping to get what works best for you. I would trust myself to do this better than a third party.

From Boston, I would consider Aer Lingus. Land in Dublin, then an onward flight to Berlin. One big advantage is that on your return, you will clear US customs in Dublin and then just walk off the plane when you get home to Boston.
As another bonus, while I upgrade to premium economy on Delta, I always just fly economy on Aer Lingus because the flights from Boston to Dublin are so short.

When I head to Europe from Boston I just about always fly BA, changing planes in T5 at Heathrow. If your Arriving and Departing flights are from T5 then Heathrow is easy. You are only dealing with one terminal. I also fly BA because it has my favorite flight. I've been flying with them for decades with no issues.