My girlfriend and I had the most terrific time at Silvia's apartment. To begin, the location is fantastic; it is right next to the Recoleta cemetary and walking distance to many shops, food places, bakeries etc and a quick Uber/cab ride to other places around time one may want to visit (Theatro colon, San Telmo).
The apartment itself is impeccably charming as the photos suggest - it is clean, with almost all the amenities one would expect at a high end hotel - remote air conditioning, digital safe, wall socket adaptors for those of us visiting from out of country, fully equipped kitchen etc. The buildling itself has 24/7 security and thus is a very safe place to stay.
On a closing note, the check in and check out was incredibly smooth. We missed our flight and instead of checking in during the afternoon, arrived at 1am, however one of her associates was there to great us and show us the place. All in all, Silvia's place is highly recommended for anyone visiting the BA area!