Welcome to Flyertalk. I just found your similarly-worded review at the top of the TripAdvisor.com page for this hotel, so it looks like you've decided to tear 'em a new one on the Internet because your expectations were unmet.
First, it sounds like you bid with imperfect information in hand. Did you understand what hotels are typically awarded for PL 5* bids in San Antonio? This information is freely available on
www.biddingfortravel.com and
www.betterbidding.com. The wise bidder sees what he'll probably get, and whether the PL price advantage is worth a little game of roulette, before putting his money down.
Second, the current promo rate at this hotel is as low as $149, per the Marriott website, which should signal you this is more like a 4* than a 5*.
Third, the Marriott Plaza is rated #13 out of 318 San Antonio properties by the TripAdvisor reviewers, so it's not appalling everybody the way it appalled you.
Fourth, it's always fraught when you use PL for family vacations because you have very little leverage re: room type, location, etc. All you're guaranteed is a room that will sleep two -- maybe a king, maybe two queens. You're not guaranteed a pool or minimum room size or any other particular amenity. That's why it's so cheap. I never use PL for family travel, only solo business travel. If you are more focused on amenities than low prices, you should not use PL.
Fifth, star ratings are notoriously squishy and subjective and arguing about whether this place deserves 3*+, 4* or 5* is like a Norm-and-Cliff debate at Cheers. It'll go on forever with no resolution. I've never been there but it looks like a strong 4* to me on the website. I wouldn't put a lot of mid-line Marriotts in the 5* category, not even the ones overseas.
Sixth, obviously there is risk with PL because they've got your money before you know what the setup is going to be, and you can't do anything about it. Anyone who uses PL more than once is aware of that.
Finally, sorry they apparently called you out as a PL guest, implying you got second-class citizen treatment, as you report in your other review. That happens at some properties and it shouldn't. I've been upgraded on PL stays, and I've been stashed in the smallest, saddest rooms in the house, and when the latter happened I didn't utter a peep because I was paying about 35% of the proper rate. All part of the game... which perhaps you should not play when family and emotion are involved.
Cheers