I stayed in the Airstream for the whole July and it was realy great!
The place is basically renovated Airstraem standing in Colleen and Dawson's garden with all the things you might expect from liitle house, that is toilet, sink, small induction cooker, quite a few electrical outlets, WiFi and air conditioning. Shower is outside and even though it might seem like a bad thing in the beginning, I really enjoyed it (I think I will install something like this in my own garden :) ). Another thing I was worried about at the start was the the air conditioning and will be be enough to cool the place. It was. Even though it was super hot in couple of days (43 C / 110 F !!!) it was able to keep the temperature at bay.
The hosts are super nice and friendly, respond very fast, and if something broke, or I needed anything they always quickly resolved the issue.
Now for the minuses with the place: the air conditioning is a little loud (and nights were also hot so it was running for the whole night). Note that this only is the problem in summer (probably). And as a side note - I do not recommend visiting Texas in July - the heat is insane.
Hmm, I can't think of anything else that was really problematic :)
Overall I really recommend the place! It felt a liitle like camping but in the middle of Austin and with all the pros of civilization (WiFi and so on...).