IMO,
Row 8 is the best Y seat on AA's 787.
Exit row 19 is another good option, but it's very busy next to the rest rooms and galley.
Rocky Horan's report has a row 19 photo at the bottom of the page.
Bottom line:
AA's 787, with 9 across coach seating, is a horrible experience, bordering on inhumane. A sardine can plain and simple.
JAL's 8 seats across is kinder.
In my experience, it’s essential to keep your feet raised during flights. And, because I use a roll-on to keep my feet up and rested, the
best seats are Row 8, D and H, with
window seats, A and L second.
I would take row 8, middle seats, B, E and K over any other seat in the Y cabin, except for Exit Row 19.
Exit Row 19, neighboring the lavatories and galley, is often very busy, but quiets down later into the journey. But, being squeezed, actually squished, between to large people, in Row 8 middle seats is not fun either.
And Row 8 aisle seats, C and J are an obstruction in the aisle, without a “proper” space to raise your feet, but it's not that much of a problem as I thought.
In addition to being an aisle seat,
my favorite seats, D and H have a small floor work area. While window seats, A and L are comfortably tucked away, and you have a large window view, but the floor work area is small, and you need to pass over two people to exit.
Having said that, many people cozy up into A/L, sleeping the whole flight, and the space between row 8 seats, and the bulkhead, is much larger than the coach seats behind, so walking over is not so bad.
That’s why I’d take a row 8, middle seat, B, E and K over the other Y seats not mentioned. With the extra leg room in row 8, it’s not too bad passing over one aisle seat. Of course, being squished tightly is not much fun.
Longed legged people have liked row 8, aisle seats, C and J. But, there is a risk for interruptions with the seat being located in the center of the J cabin to Y cabin aisle. It wasn't too bad last time I sat there.
Here is a link to
Rocky Horan's report that includes pictures and words about AA's 787.
The Row 19 photo is at the end.