Westin Europa & Regina, Venice: Used Starpoints for a standard room. Was upgraded to a rooftop room with private access to a rooftop patio and great view of the Grand Canal.
Westin Grand Vancouver: upgraded from a lower floor room to an upper floor room.
Planet Hollywood: booked the $89 special, got an upper floor Hollywood room (A Walk in the Clouds move motif).
FP Calgary West: booked standard room, received a nice king room on the Preferred Floor.
FP Canmore: booked standard room, received a very nice 2 room suite. I agree - it's the best FP anywhere!
And, my favorite: When there was the Westin Rio Mar in Puerto Rico: booked a week in a standard room for Easter Week, using Starpoints. When I got there, I was upgraded to the club floor, with access to the concierge lounge (included breakfasts, lunches, snacks, evening happy hour with appys and drinks). Definitely a bonus!

Maybe the fact that I travel solo as a woman has something to do with it. I'm always polite and never ask if an upgrade is available. They just fall in my lap.