Liked it
I did the IAH to SFO this evening (E+). There are definitely things to like with the 787. Overhead storage is excellent. Lighting and lighting ambiance was best experience in UA. I can't remember the last time I woke up from my routine 60 to 90 minute snooze without a dry throat (I didn't tonight). Looking out the windows (on an aisle seat) is quite a view. Those bigger windows definitely make for an interesting perspective. Some low tech but appreciated lavatory items. A totally unscientific conclusion (I was over the wing) yet the flight seemed quieter to me (definitely pretty noisy pre-takeoff though).
While I doubt this is the game changer that smi/j is pitching it as (surprise!), the overall experience was quite good. If the fuel savings is real, I can see this being a definite differentiator (IMHO).
I do not like the 3x3x3 but it is what it is with that.
I was fairly worn when I boarded so probably not a fair sample.... but I did not notice a jet lag difference as compared to other flights.
One of the FAs was not on her best game. Unfortunately this is something that UA sometimes lags behind other airlines I fly (and a new plane is not what will change that).
From what I recall, all bulkhead seats looked to have good legroom (though I was not looking intently for that).