Source: Lived in South Park, a streetcar suburb about 3 miles from downtown, for the last year. Enjoyed SP, but disliked SD.
Also, many people will decry my use of the word "suburb" for a place 3 miles out, but it was originally built as one and the residents have fought tooth and nail to prevent any development that would change its character or increase density. I'm sure they don't mind that their home values have increased massively as a result of these restrictions on building in nearly the only pleasant, walkable neighborhood in a city composed primarily of aphalt hellscape, though.
This is the reason I didn't move there a few years ago. I flew in for the interview, and was stuck in various traffic jams the entire 2 days I was there. The economy there is booming, so it's not like the traffic is coming from a bad place, but I'm not keen on hour-plus commutes.
First, downtown Austin is now actually more expensive than downtown San Diego. When people say "Austin" and "cheap housing" they mean Round Rock, Pflugerville, San Marcos, etc. Many of those places are now an hour or more commute to downtown Austin in horrific traffic that now rivals Los Angeles. When people think "San Diego" they don't mean commuting from Ramona or Temecula (an equivalent hour of horrific commute).
Second, Austin has some culture, but has been working overtime to flush it down the drain. Stevie Ray Vaughn would be an unwelcome, dirty scumbag on the current 6th Street. Medium sized venues (300-1000 people) that launched major music careers are becoming very scarce (I blame smoking bans mostly). And most of the "cultural" catering is to overpaid DINKs (Dual Income--No Kids) who want desperately to be so cool yet complain about the noise from the very places that they moved in next to in order to be cool.