I stayed at the Riverwalk just a few days ago, largely based on comments from this post. Never again. No perks, not even any recognition of status. Rooms are unbelievably noisy, so much so that they leave a note telling you to ask for their "sleep tight" package, which includes earplugs. Also a little teddy bear to take home, which was a nice touch but I'd rather have a good night's sleep. The sound machine, which didn't work very well for me, you don't get to take home.

Staff was nice, but housekeeping was lacking--my room was literally crawling with ladybugs! Being a tree-hugger, I rescued all still alive from the windows, walls, curtains and floor, and took them in an empty water bottle to a tree far, far away (i.e., outside Houston!). I obviously need more to do. But would I ever recommend this hotel? Not a chance. And too bad, because I love the location. Not even sure Rivercenter is worth a gamble next time.
On the plus side, I also spent a few days at the Plaza San Antonio for old time's sake, and it was excellent. It's only about a block to La Villita and thus the riverwalk, plus much quieter location, nicer surroundings. Love that old place. Be careful where you stay.