I work for Fairfax schools as well and my mom has lived in Austin for the past 25 years.
Believe me, traffic in Austin, while bad at times is nowhere as insane as it is in NOVA. Good thing about Austin is that even in high traffic times you can still take the side roads. There aren't rivers all over the place that are only crossed by two or three bridges.
I am ready to move back to Austin and will be doing so this upcoming summer. If you have never lived in Tx, you will get a year to take your TeXes tests, so make sure ya get on that.
From what I know, I prefer the NW part of Austin over the south. Dell has really brought a lot of changes in the North.
For info on districts put "Texas Regional Educations Service Centers" in Google and go to region 13 (I think that's Austin)
if you need anything else drop me a line at:
umgoblue80@yahoo.com