Well, I've never been to Ohio but I'd imagine SA is pretty different!
I think it's generally a nice place to live, very much a family oriented city. Compared to Dayton, I believe the cost of living is fairly similar. Our real estate is pretty cheap but it looks like Dayton has similar prices. The biggest difference is probably the weather. Like PP said, it's VERY hot here in the summers (which pretty much start during what everyone else considers spring) and the winters are very mild, rarely reaching freezing and snow makes an appearance once every several years.
San Antonio is a large metropolitan city but still feels somewhat like a small town. Traffic is normal, not great and not terrible. There is currently very strong job growth here compared to many cities and stronger even than the larger Dallas/Houston markets (I'm a recruiter so we study these things ). That said, there are a lot of lower level jobs here and less "white collar" jobs however, there are some larger companies moving their headquarters here in the next few years and that's expected to continue our job growth within healthcare, accounting/finance and technology.