I flew it in Biz last week from LHR.
I feel so much has been written already so just trying to be incremental.
I chose 14A which gives you rather good privacy given that you face the window, with a table separating the seat from the aisle.
Conversely those solo seats which face the aisle have close to zero privacy. The same goes for the "honeymoon" duo of seats, where you end up sitting very close to the person next to you. The aisle in J are very narrow, you'd have to step into someone's pod to let someone pass.
In past reports people mentioned that LY was providing noise cancelling headphones, here they provided the regular old ones in the storage units next to the seats. Maybe I was supposed to ask for them but I didn't care since I carry my own set.
Entertainment has roughly 150 movies, with a mix of old and new ones, and the system works from the second you board (as opposed to the old LY where they waited for the system to be above 10k ft before turning it on).
The Premium Y and Y where half empty so I went and tried a few seats. The Premium Y felt very comfortable with lots of space for the legs and nice individual screens. Definitely much better than Y but I hear it's also much more expensive.
I felt Y wasn't as bad as I've been reading, but again I only say for a few minutes as opposed to people seating over 10 hours from Newark. Row 21 which is right behind Premium Y has significant leg room.