An excellent apartment in a residential neighborhood, close to the subway and to many shops and everything you would need. Having stayed in many parts of Buenos Aires, I have to say that Caballito is my new favorite neighborhood because of its central location. You're basically in the middle of the city, so you can get anywhere in about 30 to 40 minutes. The apartment itself has an amazing balcony/parrilla with ample space for a group gathering. There's nothing better than being on a balcony with friends enjoying steak taken right off the grill. We were a bit afraid of hearing noise from the pool above, but that turned out not to be a problem at all. The apartment was in need of a few updates; the refrigerator was running colder that it should and the air in the living room was weak at times. (We started using a fan to augment and that worked out fine.) By the way, the apartment gets a great breeze on many days, so many times you don't need the air conditioning! But the best thing is that the owner Gabi is on top of it all. The apartment is her second home, so she is eager to take care of any problems that arise. Having a washer and dryer available for free use in the basement is great. Also the pool on the roof is cozy (read: small), but wonderful for a quick dip on those hot summer days. The internet connection (Cablevision Fibertel) was the fastest and most stable I've ever experienced in Buenos Aires! Kitchen is well supplied. Couch is comfortable. We really enjoyed our time in this apartment and highly recommend it to anyone looking for a place to stay!
One small thing to be aware of: The water pressure in the shower is kind of weak. I doubt anything can be done about that since it's probably an issue with the building water pressure, and the fact that the apartment is on the top floor. For us it was not a big deal, but mentioning it in case strong shower water pressure is important to you.