Just stayed in this hotel over Labor Day weekend and was very pleased. As a convention center hotel, it didn't seem very busy as we expected for a holiday weekend. Others have indicated it is off the beaten path, which we didn't find to be a problem since it is a nice stroll or river taxi ride to all the Riverwalk restaurants and shopping.
As a Diamond, we were upgraded (without asking) to a "Grand Suite," which consisted of 2 connecting rooms, one of which had a bed, bathroom, lounge chair desk and TV, the other had a large Queen sofa bed, coffee table, full bathroom, desk and TV. Having the extra bathroom and TV worked out nicely traveling with our teenage daughter. Suite was on the 21st floor with nondescript city view. Soundproofing was very good. Our bedroom was adjacent to a mechanical room that was quite noisy in the hall, but we couldn't hear a thing inside our room.
The Grand Club on the 23rd floor was very nice and has a great view of the Tower of the Americas. Their coffee machine is the best I've seen at a Hyatt. It is very fast and offers a nice variety of latte, espresso, capuccino coffees. They keep refrigerators stocked with water, soft drinks and juices to help yourself to throughout the day with an honor bar in the evening. Breakfast was a nice assortment of pastries, bagles, fresh fruit (Sliced pineapples and papayas reminded me of the clubs in Hawaii.) Huge cookies were offered mid day with cold hors d'ouvres and delicious desserts in the evening.
We found the service at the hotel to be excellent, although there seemed to be an issue with the posting of our GP credits, which a call to CS rectified. My DH is staying at this property on business next month and has already been notified he has been upgraded to a suite again. They do treat their Diamonds well there!
You can find some great offer codes for this and other San Antonio properties at the San Antonio Convention & Visitors Bureau website: visitsanantonio.com.