I flew LH this winter FRA-PEK (more than 10 hours) and even if the new IFE is really great, the new seats are really hard and it was horrible for a 10 hours flight. The way back was really better since I was upgraded to their new Y+ product which is indeed great (and definitely better than BA Y+).

I flew KL two years ago back from HKG. The flight was pleasant since the cabin was half occupied and nearly every passengers had 2 seats for themselves.

But for Y, I really prefer flying BA (not on the 787) or EK (back of the 777 or front of the A380). EK give you the opportunity to choose your seats for free at the time of booking and have a really great service onboard.