I have been living in Austin for almost 4 years, a transplant from NJ. We have lots of visitors and this is the second time I have taken out-of-towners on this tour in less than 2 months. Sans having a private tour, this is the most comprehensive overview of Austin that I have seen in just 90 minutes. Our first tour guide was Rocky -- he was pleasant, thorough, and a safe driver. On the second trip we had Maggie, a TX history fanatic with an incredible knowledge of Austin. I will request her for all of my future tours (she currently works Thursday and Fridays).
This is, by far, the best bang for your buck if you only have a short time to see Austin and need a good overview of the city and its surrounds.
PS - check out the Visitor's Center -- lots of helpful information about Austin!!!
Pros: Tour guides, A/C, Multiple points of interest, comf. bus
Cons: Can't get off at each spot to see sights
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