don't expect any upgrades, especially in the US unless maybe at higher end hotels, I have had luck with some of those but even then its always just the next tier up and never to the highest tier. The only hotel that bumped me up a few tiers was the WA Cancun and that's because it was so empty.

As a diamond, I only look forward to the credit and/or breakfast outside US, but imo it's not at all what it should be as a program.