[Bozza]

Yep - used it many times, most recently to get a Hilton in San Francisco last year.

As above, better bidding can help you identify the specific hotel with a high degree of confidence, but you have to be prepared that it might not be a specific hotel that you want.

Because of this small risk, I always go for 4/5* as I'm unlikely to be disappointed with any hotel of that standard I get given.