Sylvia's place was a perfect base for our four nights in Austin. It's clean, comfortable and well connected to the rest of the city - we ended up walking everywhere. It's particularly close to Rainey St and the main downtown area.
One very small criticism was that Sylvia was a bit difficult to get in touch with before checking in, but we were able to reach her eventually so it ended up being a non issue.
I would definitely recommend this place to anyone considering a trip to Austin.