Super easy to book. Julian and Melisa always responded super quickly and they were 4 hours ahead of us at the time of booking. The apartment felt much bigger than it looked in the photos! It had everything we needed and the beds were very comfortable. The tango show Julian suggested was a great deal (dinner, transportation, show, and all you can drink wine).
Location wise, I don't think it gets better. Right next to Chile street where the best restaurants are (Cafe San Juan) and some really great bars (Red Door). Also on Bolívar street, head south and you're at an amazing market with phenomenal coffee (Coffee Town), delicious empeñadas, and a bunch of old antiques and cute gifts. Head north and you get to a square that has events from time to time. About a 10-15 minute walk to the water/reserve and easy for Ubers to get to.
Julian was very accommodating and I would definitely book with him again if I return. I would also host him in Arizona if he ever decides to visit! Never bothered us, but provided enough information to feel helpful but not over bearing. Great guy!