Funny this topic comes up when it's the lack of an upgrade that was the catalyst of me reducing my stays with Choice.
I consider an upgrade booking the cheapest room and getting a more expensive room at no additional cost, so I always play that game. Some hotels just don't really have anything to upgrade to, though. So, here are a list of places I've stayed that had upgrades available and gave them to me:
Comfort Suites - Haverhill, MA. (they upgraded me before I even walked in the door, one of the best properties out there for recognizing Elites)
Comfort Inn New Stanton, PA - occasionally.
Comfort Inn Greensburg, PA - always when available, but since their upgrades are to jacuzzi suites and I'm generally traveling solo, I pass.
Sleep Inn State College, PA - no real upgrades, but they'll give you a preferred room if you ask.
I would say that I get an upagrade at about 40% of the properties. Generally, though, no one even realizes that I'm diamond unless I ask for an upgrade. Choice is terrible at recognizing their elites, IMO.
And the one that really ticked me off and led to me use other chains?
Comfort Inn (PA400)
3191 Highfield Drive, Bethlehem, PA, US, 18020
As I've documented before, they had three opportunities, on three different occasions, to upgrade me from a two doubles to a queen room (a cost difference of $4 a night), and they refused (unless I wanted to pay the difference). That policy has cost that hotel over 40 nights in the last 3 years, and has cost choice at least a hundred over the same time frame. Now I only stay there during points promos, and even then I'll pass the points most of the time...