Just thought that I would add another opinion regarding economy seats and service. I flew TXL-MIA a few weeks ago (then onwards flights, and back to Europe CLT-FRA on US). I was traveling on business, but I wanted the points and AB had the cheapest ticket, so everyone was happy. The comparison between AB and US might be useful since they fly the same plane, just in a slightly different setup.

I found the AB seat itself not so bad... I have been in worse LH seats, especially on the older 744s. However the missing 1-2 inches of legroom compared to US or other carriers TATL was noticeable and not so pleasant (I am about 6'0", the lady sitting beside me at 5'8-5'9 was definitely more comfortable). I actually found the IFE very good. The screen quality was nice, the selection was OK... better than the IFE in an LH flight a couple of months earlier. The food was quite OK for economy class (definitely better than US), but gets a minus point for crackers rather than a roll/bun. The service was fine.

I might fly this again when connecting through JFK or maybe ORD, but for longer flights like MIA or LAX that bit of missing knee/leg room is a real problem.