Last week 777 BOS->SFO (Version 5 or 6 per https://www.united.com/web/en-US/con...0/default.aspx)

Most miserable flight EVER. Avoid like the plague. 3-4-3 seating is so narrow that you need to twist sideways, if you want to avoid constant intimate arm rubbing. Flat line seats are very hard and have almost no recline. Personal device entertainment can't keep up with that number of passengers and doesn't work most of the time anyway.

Return flight on 737 (don't know which one), was much, much better.