Westin Grand is a suite-only hotel so the worst room you might get will probably be a lot bigger/better, and definitely more luxurious, than the average Hampton room.

I've stayed at all the main YVR properties: Westin Bayshore, Westin Grand and Sheraton Wall Centre.

IMO,
-SWC is best if you are Plat and want lounge access for free brekkie and evening snacks. High probability of suite upgrade too. Good location.

-WBay is best for families, near harbour, good views. Slightly poor location for downtown shopping etc.

-WGrand: best location IMO. Short walk to Robson st, shopping, bars, Bay/Sears etc. Classiest rooms of the three properties. Food more expensive than the other two, but much better quality. Prob the best hotel for a Gold, as it is an all-suite property!