The building is near the intersection of Tacuari and San Juan in San Telmo and conveniently located only 1 block from a Subte C station that connects with all the other lines. It's approximately 5 blocks from Paza Dorrego and 6 blocks from the San Telmo Mercado. I was entirely comfortable walking in the area night and day.
The monoambiente was furnished stylishly and the kitchen was more than adequately furnished to prepare meals, coffee, etc. The AC functioned fine. The WiFi was strong and there was a a loss of service one time that was easily remedied by disconnecting and reconnecting the router. Hernan, who was the point person for the rental, responded quickly and helpfully when I contacted him. Likewise, Hernan made both check-in and check-out extremely easy.
I was not able to use the building laundry when needed because the one washer and dryer was in use, but there are several lava ropas nearby and it wasn't a serious inconvenience. It's a large building with many units, but noise was not a significant problem. Entry to the building requires a key fob and a 'virtual' guard on a video screen sees you as you enter the building.
I rented the monoambiente for one month because there is a pool and solarium. Unfortunately, the height and placement of the 2 building for this property prevented direct sun exposure for all but a brief time in the morning and around 1.5 hours in the afternoon. This was the only disappointment I had during my stay. No direct sunlight fell on the spacious balcony during any time of the when I was there.