I was on AY41 on the A350 the other day. I'm 5ft 7 so not that tall, but am not small, and I found the plane reasonably comfortable and was able to sleep just as long as I do on the A330 (returning on one of the throne seats towards the end of this month). The plastic grill below the footstool is ridiculously flimsy and every seat I saw had the telltale signs of grey duct tape.

I was able to sleep on my side with no problem (my normal position). Pain in the neck having to put the seat almost upright to get in and out of the seat though. That part hasn't been thought out well at all. I also had a very well cooked reindeer fillet - by well cooked I mean nice and pink and juicy, not well done as I have had it on the A330.

Apparently according to CC they are going to be dealing with these vents at some point.