Austin has it's good points, it's gained it's share of problems in recent years. Full disclosure - I've lived in Austin for over 5 years, many of my friends have been here for 10+. I'm looking to make a move back to one of the coasts in the next year or so.
1.) There is the climate. As I type this, it's 106F (40C) right now. It could be worse. It hit ~114F last summer. There's an awful lot of blacktop and concrete out there that's just baking in it. Walking around outside and breathing feels a bit like I'm inhaling from the business end of a hairdryer. I looked at the temperature around midnight last night and it was 90F. The hot season here makes going outside almost useless unless you REALLY like to sweat and/or gain skin cancer. Granted, the winters are mild and generally pretty pleasant. It's rare to see more than a dusting of snow, and that's gone within hours. Also...we're in a drought. The growth here is outstripping the water supply. The lake getting so low that you can't even see water from some of the boat ramps.
2.) It's mostly super cool in that most people say it's super cool. They have great marketing...I've give them that. Most of the originality here is gone...now it's just trendy. Thankfully I was still here in the days of Leslie. (A well known local homeless cross-dresser that ran for mayor once, among other things.) "Keep Austin Weird" used to have meaning. Now...most of the original old businesses are fading away. All they do is build more condos and gated communities. Seriously...the architecture isn't even aesthetically pleasing. (A bit subjective, I know...but I think most would agree.)
3.) Speaking of condos and gated communities - this is "business friendly" Texas, so the developers are running almost unchecked. They want to squeeze every cent they can out of everything they can get their hands on, and they generally do. Developers here seem to be able to throw up any size development they want, and they aren't asked to do very much with respect to infrastructure improvements to keep up with the growth. Want to pack more cars onto an already overtaxed highway? No problem...build baby build. When it comes time to address the roads, the tax payers will get the bill, rather than the even-more-wealthy developer.
4.) Culture. Austin is not really a mix of SF - Berkley, Boston, or DC. I really have no idea where that idea is coming from. I've been to all of those places and spent a fair bit of time in one of them. (DC)
5.) Traffic. Austin has been rated as the third worst area for traffic in the U.S. recently. Right behind LA and DC. Some people don't believe it, other people are screaming it from the hills. It depends on where in Austin you are, and where you're trying to go. Try driving around on 360 during rush hour. It's gridlock...and in summer, it's extremely HOT gridlock. Hope there isn't an accident, because it'll only get worse. If you drive a small economical car, bear in mind that this is still Texas. Probably 50% of the vehicles on the road here are gigantic pickup trucks, or yuppie luxo-barges.
6.) You're still in Texas. Did you follow the news lately? Wendy Davis barely filibustered in insanely tight abortion law that is about to be passed anyways. From what I've read, they're going to be down to about 5 abortion clinics in the state of TX. (Seriously...the state of TX is huge. It takes 12 hours to drive across it.) Glenn Beck just moved to the Dallas/Fort Worth area, and he's been telling others like him to come here. The Republicans are calling the shots. It's a low-tax, low-service state. If you move here...you're ultimately going to get what you paid for. There are no free lunches. Ironically (for most Slashdotters)...if you're moving here and cite the financial reasons, you're proving the Republicans correct in many ways. Good luck with that.
Anyways...I've had a decent time here, but it's getting to be time for me to move on. The BBQ is great, and you can rent a machine gun at the range and go to town with it.