I'm a LTP, not PP, but I've gotten upgrades including to suites. Sometimes upgrade is to exec level, sometimes to larger room, sometimes to jr suite or suite. Is it every time at every property? No. But I don't know any program that does every time at every property. For me, having lounge access is more important.

I learned something from this thread - you can get IHG Plat with a $49 MC, although it doesn't sound Plat gets you all that much given some of IHG brands. Sounds like it would be a no-brainer to just get the MC & then one doesn't have to worry about hitting the nights needed.

If the OP decides to switch to Marriott, he definitely needs to get the Marriott Visa (sign up for the one with the 70,000 sign-up bonus if it's still available) given his stay pattern. The 15 nights credit plus 40'ish nights would get him to Gold. He could also try the Road to Gold Challenge getting the 6 stays & then have Gold through Feb 2016.

Cheers.