I had a lovely stay at Martha and Trey's!
They were both easy to commute with, and answered all my questions in no time. Just really nice people!
The flat is perfect for one or a couple. I stayed there during SXSW, and because they've put in a small fridge, I never missed access to a kitchen. The bed is super comfortable and the bathroom is great. It's easy to get a taxi downtown. City bikes are also located close to the flat, I just never used them myself. I walked a couple of times, which is no problem if you have 40min to spare!
There is a great grocery store close by, as well as cool restaurants.
I would highly recommend this flat, and would stay again, if they'll have me;)