Not sure if it is still a Westin, but stayed there when it was one about 2 yrs ago. It's a great hotel (but not luxury by any means), secluded, private-ish beach (so no constant peddlers), interesting architecture, OK food, great pool, nice jungly setting. Don't remember anything bad about the beds...

Villa del Sol has a great restaurant, so definitely go for dinner. Also La Casa Que Canta is great for food. These places are both in Zihuatanejo; the Brisas beach is most definitely nicer IMO. It's the only hotel on that beach, and the surf is good. We actually experienced an earthquake while on the beach - deep thumping sounds followed by intense vertical shaking... 10 minutes later all these marine plants & algae were washing up on the beach en masse...