Myself and my husband stayed at Matthew's casita for five days while we were on vacation in Austin, and were very impressed!
The space:
Very clean, small but efficiently organized (we never felt like we didn't have enough space) with linens , towels, toiletries and a few snacks provided. Bed was very comfortable and there were four pillows (which is very appreciated, as a pillow snob). Kitchen had dishes, utensils and stuff for cooking. There was also an armoire for storing clothing.
The TV seems a little small in photos, but is actually very well sized for where it's mounted. It's also a Roku TV, as an added bonus.
The host:
Matthew was a very communicative host - we had a minor air conditioning issue while we stayed there, and he immediately took steps to address the problem, including bringing an electrician out to see what the issue was. He was very attentive and made it clear that he cared about our experience, but without being overbearing - important when you're staying in someone's backyard! The location was also great, being about fifteen minutes away from the airport and downtown. We would definitely stay here again!