We stayed in Gustavo's apartment for 12 nights and really enjoyed it. The apartment is very well located, I think the best in buenos Aires because it is close to Palermo and to the city center, so you can reach everything quite easily. Subway stations are nearby. Gustavo arranged a taxi picking us up from the airport and fetching us the day we were leaving again for a good rate. I would recommend to use this option, it is also very comfortable. He also gave us good advice and a very helpful map when he welcomed us personally in the apartment. You can always reach him via whatsapp during your stay, he answers fast and is motivated to help with anything you might want to know for a perfect BA-experience. The wifi by the way is very good as well. The bed is comfortable, the bathroom is small but totally ok. The apartment was cleaned once while we were checked in, which I considered a very good service. We even found it cleaner than the day we arrived. Even though we knew that from the beginning it got annoying with the time that we did not have a normal dining place in the apartment, only bar chairs. Since we were there in the Argentinian winter time it wasn't very warm and probably not the time to be at the pool for Argentinians, but it also wasn't possible to use it during our stay because it was absolutely dirty. I guess in the summer it might be different but if you go there during the winter don't expect to be able to go there.
The last thing is about the oven. It is a gas oven and worked normally until some days after our arrival, then it started to smell a lot like gas in the entire apartment while cooking a small meal, we even had to stop because it was so bad. We contacted Gustavo who sent the janitor to "fix" the problem. He closed the security knob which we always did by ourselves before, but the smell while cooking wasn't gone. Gustavo told us he would come over the other day but never appeared, so there was no more cooking for us for the rest of our stay.