Debra, I worked in downtown Austin for 24 years (commuted from San Antonio for 9 of them) and try to avoid downtowns anywhere. No problems with going downtown in SA - we do once in awhile. In fact, there is a shop in downtown SA that is the only place I purchase clothes for my husband - Penner's.
It's really pretty along the river - we do take visitors there - and if you get a chance you should go on the Mission tour to see all of the Spanish missions - it's worth the time.
I just prefer less crowded places - in fact, if I could move to our farm that is about 30 minutes south of SA, I would do that. Just not feasible right now.
SA is really a lot of fun.