We loved staying in this loft in the center of Buenos Aires.
It is furnished tastefully, so our first impression was immediately positive. There is a long mezzanine with a double bed and a single bed at each end, plus two single beds underneath, at the same level as the kitchen. It is all one one big room, but these different spaces make it feel more like a small apartment. The air conditioning works well (great for summer naps, my daughters loved it).
It is very close to plaza de Mayo and to the subway. It is only a few blocks from San Telmo, for example.
We didn't meet Mimi, but a lady was waiting for us when we arrived and we received a bottle of Argentinian wine as a welcome present. Nice touch. Also, Mimi was helpful trying to find a solution for our transfer to the airport very early on the 1st of January!