The Alamo is boring. idk, I guess it's one of those things you just have to see but I don't give one frick about Texas so I don't care about its independence and all of that. I think Texas people, for the most part, are lame.
That being said. I really enjoyed my time in San Antonio. We made the mistake of driving.
when we went a few months ago. I took my family to SeaWorld which was a lot of fun! But I don't know how great it is if you don't have kids.
Shopping wise, The Shops at La Cantera is a MUST. Definitely one of the best shopping experiences I have ever had, I rang up quite a bill. My wife went nuts too! AVOID IF YOU DON'T WANNA SPEND MONEY.
Cool city overall. I think you'll have fun!