Location wise, the Hampton is almost right next to the Westin. About 300 meters away, I'd say.

I've stayed at the Westin Grand and liked it, but what's important to you? Because Hampton Suites tend to cater to different travelers than Westin. If you need roomy accomodation and free breakfast, go for the Hampton. If you like posh bathroom and superior service, I would choose the Westin.