Y on the AA 788 from ORD to PVG was about the most uncomfortable long-haul thing ever.

Biggest complaints, to echo others:
-Seat pan too high; I'm 5' 7" and there was too much pressure on the back of my legs for me to stay still for more than 5-10 minutes. On the other hand there was no way I was getting a DVT on that flight.
-Seat back too short. Again, I'm 5' 7"...and a fully extended head rest still wasn't tall enough.
-IFE was fine, one of the most responsive I had used, until the person in front of me reclined. Who decided that non-articulating screens should ever exist?? So then I reclined. But the seat backs are short right? Yeah.
-Not enough bathrooms (okay so this isn't related to the seat).

Plus side was the lack of an IFE box.