We stayed for 1 night at Mariano's Place.
In fact, Mariano was very responsive when it came to the booking.
every time we needed some additional info it didn't take more than 1/2 hour to get a reply.
We were lucky enough to get an "upgrade" to a bigger apartment that Mariano owns in Palermo.
The apartment was excellent: Very bright, spacious and clean.
If we return to Buenos aires, we will definitely return to his place.
Thanks
Johannes