I flew the 787 EDI-DOH rtn for 2 years every fortnight, mainly in Y until I started hitting some of the J sales and upgrades.

Compare it to the older 777/A330 Y the 787 is actually light, airy, and the IFE screens are pretty good. Its not all doom and gloom. Personally i compare it to the other competitors out there. BA for example are horrendous in Y long haul. I found if you get the very last row of Y with 2 seats its was much nicer on 787 as you had more room to stretch and actually have a decent flight, and you can step into the galley and chat to the crew if you're bored!