If you land at night, Charlotte's place is like 15min from the airport. (It's about a $20 Uber/Lyft). I though this would mean we would be a little further from the South Congress action but her place is quite walkable to the shops and restaurants on South Congress and then to the river from there. About 15min walk to where everything starts picking up and the maybe 30 total if you are walking straight to Riverside. I imagine this would be a super hot walk in the summer though and it might be worth just riding over for that. Charlotte's place is also a short drive to the East Austin area. We spent some time on that side of town as well and each time it was like 15min from her place by car (if you aren't in traffic).
In general the room was very clean and she had toiletries, a high dryer, and an iron available if you need them. There is also a binder with things to do and a TV in the room. Charlotte was very helpful with any questions we had.
We had a super pleasant stay and would stay at her place again any time!