I like the PVG Air China lounge. Upstairs and through the hamster tube near Gate 71 thereabouts? Go upstairs once inside for the food. It's better than any UA lounge I've ever seen (caveat: haven't been in any 1st or Polaris lounges). IMO, the PVG lounge food selection is on-par with the bigger SQ, LH and LX lounges. I don't remember any nice beers on tap. No whisky bar like LX at ZRH. No gourmet chocolate demo like SN at BRU. Food's not as nice as the bigger QF and NZ lounges--those guys take their gastronomy quite seriously.
I've gotten airside by about 7 or 8pm before the after-midnight PVG-SFO flight. Never tried earlier.