Hey guys, first timer on United.

Taking 12:20 LHR- SFO in seat 27A Economy with the 772, how is the seat pitch and service and how does it compare to BA?

Doing 21:15 SFO-EWR on the 752 seat 22A Economy, how is the transcon overnight, any food? Or do I have to pay.
Looks like there is an Amex centurion lounge, so probably will check that out before my flight, any good?

And finally how is the 21:00 EWR- LHR on the 763, seat 32A Economy.

Thanks for any tips!
I have done 77W LHR-LAX with NZ and also with BA on the A380, so any comparisons or anything of the sort would be much appreciated!