Had a two night stay as a new diamond. The FD staffs were polite and pleasant, the service was good, the room was clean and comfy. Didn't get any upgrade though.
The only downside was the Regency Club. Compared to the Lounge at San Jose Marriott, where offers all kinds of alcohol and non-alcohol drinks, ice creams, hot breakfast, the Regency Club was not up to Hyatt standards.
However overall it's a decent hotel for business stays.
I'm guessing you stayed there more than two weeks ago. I think the Regency Club is entirely gone (temporarily?) now.