I stayed at the Doubletree as a Gold and didn't get much of anything. My room was very nice, but I don't think they have any upgrades available for Golds. Actually they wouldn't honor the increased check cashing limit for Golds.
The hotel is nice though and the staff has always been very pleasant. Even when telling me that they couldn't cash a check for more than $50 they did it very professionally and with a smile.
On a side note - that was the only time I ever tried to use the check cashing priviledge, is that common? I was having problems with my ATM card, so a check was the only way to get cash. I was forced to write a check for $50 every morning instead of the increased limit.