Actually, you're wrong. It is, indeed, a huge issue. The four guaranteed suite upgrades are clearly what makes Hyatt Diamond stand out right now.

I had a similar situation with the Grand Hyatt during Christmas-New Year's week. I asked them to call the hotel and see what could be done. It took maybe 15 minutes but the eventually came back on the line and I was reserved in a higher level suite than I ordinarily would have gotten.

This is a MAJOR perk. Don't give up so easily! Ask the Diamond rep to truly represent you here. And try to think of a good reason behind this trip - big anniversary, big birthday, etc. Most of the reps I have spoken with really do want to help - you just need to ask.

Good luck.