I just had three segments on a 787-10. First one was a window side (9A) SFO-EWR. I found the seat very narrow, especially when in the lie flat position. As a broad-shouldered. 6'/200# guy, I couldn't fit my shoulders comfortably into the coffin because of the narrowness of the space. Next segment was to Europe and I picked 11D, which was an angled middle seat. I found the coffin much more roomy when in the lie flat position, and way more comfortable to sleep. The privacy between 11D and 11G was, only a small shared wal, and with the divider up there was no hint of a person on the other side of you. For the third segment, I chose that same seat again over the window adjacent odd seats for that reason. If you are wide, I would definitely recommend the middle section as it seemed to me there was more width - I think the fuselage wall on the window adjacent odd numbered side seats causes the narrowness.