Most of my TATL trips involve a redeye going east, which makes the seat #1 on the list of priorities since I use that leg to "sleep". Another variable to consider...now that BA flies a 789 EWR-LHR I try to book that flight in F if I can get it, especially for the redeye, since I find the modest differences in humidity, noise, and cabin pressure make a huge difference for me while sleeping...makes an even bigger difference for me on TPAC flights (for which BA isn't an option for me being US-based). Flying west I'm probably trying to get some work done, so seat comfort probably wins again. I guess I tend to focus on service differences more for leisure trips.