I flew the 787 yesterday to ICN and found it a mixed experience.
Seat 3A is very good, the extra length while in bed mode was appreciate. It is private and has a great view of the wings. I think it is the second best seat in the fleet after 64A/K.
Having said that the aircraft is not as pleasant as promised: the increase in air quality is noticeable however it is not that quiet. The A380 is better on that aspect. It is true the fuselage rattles a lot in turbulences.
Also it is not as smooth as I expected, might have been the weather though.
Toilets access is a pain, not enough of them. The sensor flush is kind of fun.
The worst are the windows. They do not block enough the light even when set on darkest. Also they reflect IFE screens and other sources of lights. The cabin was not dark enough for sleep. I would avoid it just for that.