It really is more of a 4.5 stars review than a 5 as there are big PROS but big CONS as well.
The great PROS: location (I am originally from BA and I think that Las Cañitas is among the best places to stay in BA), the back of the apartment faces the polo field (really nice!), and the decoration is nice and homey (not always the case). Pablo manages the apartment. He was excellent, very responsive and kind.
The apartment was very clean and the building is just ok but not bad at all.
But, the apartment also has a few big CONS and some other not so big ones as well.
Big CONS: the smallest fridge I have ever seen (ridiculously small), the smallest water heater as well (barely ok for one person, but two people cannot shower one after the other).
Other CONS (they get to you if you stay long): no stove/oven (just a small electric one, not important if you don't cook at all), small sinks (bathroom, kitchen), lighting in the living room is awful.
All in all, it is a good apartment that could have been great. If you only plan to be in BA for a few days, it is a great place to stay unless you are a large person and struggle with your size. I am 6'1" / 210 pounds and rather athletic so I could manage fairly well. If you are big and have physical issues this apartment may not be for you. You will find the bathroom quite uncomfortable as everything in it is small.