Javier's place was great. We loved the neighborhood (Recoleta), with several nice restaurants, bars and ice cream shops next door, a supermarket and pharmacy, and very close to a subway station that takes you to the city center in less than 10min.
The apartment was wonderful, spacious and modern, with a great shower. Javier was super thoughtful and pleasant to meet. He provided us several tips about the neighborhood, the metro and the city, and even lent us a reusable shopping bag and a metro card so we didn't need to buy a spare one. And he had turned the AC on prior to our arrival, which was a great touch since it was a super warm day!
We highly recommend this place and we would stay again if we come visit Buenos Aires again in the future.