To answer my own message

- There is a wall between J and Y that only goes up to the seat headrest level, with no divider curtain between J and Y. There is plenty of space but if you are one who likes to put your bags under the seat in front or stretch your legs out, this may be limiting for you
- B seat did not really seem to be an issue, but wall is less wide on AB side so B seat could stretch legs out (watch carts!)
- The plane switched constantly between the 9 and 10 seat J version, so I picked row 5 and then on day of travel it turned out to be the 10 J seat version so row 5 was the first row of Y. I would probably continue to pick row 5, as I would hate to be pushed right to the back by a late aircraft switch.

Kf