Yes, I agree with this, rather than the previous poster. Having flown in UA F, FRA->SFO 3 weeks ago:
(a) Seat is great! (not just good). Two pillows, one large and one small, and seat padding in all the right places IMHO means that you'll get a great night's sleep. (no pajamas, but I have several of the cheap ones they give you on VS if you're desperate)
(b) F has a huge amount of personal space, including 3 storage bins: 1 large and 2 small. No, I haven't been on those Emirates first suites that we see advertized, but believe me, the hard product is really good in UA F.
(c) I thought the food was quite good. No, not restaurant fine dining, but comparable to meals that I've in premium classes in BA and VS recently.
(d) As far as service, UA's major challenge is *consistency*. It can be very good - I hope you get some of the SF-based male FAs - they seem to be the best (for some reason)
Have a nice flight!