I enjoyed my time staying in the casita on Avenue B. The location was great for my daily commute, finding good restaurants, and completing errands. I also appreciated the surrounding garden and the overall quietness of the neighborhood.
I stayed during the summer from the end of May till early August. During this timeframe, it was recorded as the hottest July in Austin history. From my experience, I can confirm that the AC in the casita works really well. If you are staying during the summer it may be beneficial to get an extra box fan and point it upwards towards the loft bed because that area can get a little warm during the day.
I also cooked dinner at home for the majority of the nights during my stay. The kitchen has plenty of utensils, dishes, etc. to use. The stove top is a little finicky - I had it stop working a couple times during my stay. I would recommend getting a cheap foreman grill to cook chicken, burgers, etc.
If you are planning to work from home during your stay, just note that the WIFI is fairly slow and a little unreliable. The place has a great quality TV though, and the couch is comfortable.
There's plenty of storage space up in the loft and in the closet.
If you are staying for longer than a week, you will probably need to sweep because the granular rocks forming the path leading to the casita are difficult to avoid tracking in.
I also had quite a few bugs inside the casita throughout my stay. During the first 6 weeks, I killed a couple earwigs almost every day. Then, during the second 6 weeks, I had to a kill a couple cockroaches. I also had a ton of baby cockroaches show up. For a little while, every morning I would find a few lying dead in the bathroom. However, they lessened considerably during my last two weeks.