We lived in Houston and Austin...visited all of the other big cities many times. I would say to visit Austin without question. There is so much to do and experience. Dallas is also very nice & classy. San Antonio can be enjoyable for a day. Houston was described to us many times as the "armpit" of Texas and we felt the same after moving there. Lots of traffic, run down buildings. You are either oil wealthy or dirt poor it seemed. NASA and the Seabrook boardwalk are fun, but Galveston's beach is brown and not very desirable.

There is so much more to Austin than just downtown Austin. Check ahead of time to see what events will be happening at the local parks. They are great about organizing activities and music events. If you make it there, I would recommend also visiting Hill Country. The views and restaurants are A+.