I was 6 days in Santiago's apartment with my b-friend and had an excellent experience. The flat is luminous, the living space is pleasant and large enough, with a modern kitchen. The bed is perfect, king size and oh-so-comfy, bathroom also great, air-con top notch, as well as the Wi-Fi.
Well located close to Palermo's restaurants & boutiques, it provided us an ideal base. We felt in security in the area and in the building.
Tango aficionados like us will appreciate that major milongas and schools such as El Yeite, La Viruta, DNI, La Maleva, etc. are at walking distance. :)
Santiago's communications were prompt and efficient. We met him on our first day and found him very nice and eager to help us if needed. We were stuck with our luggage on our last day because of a very late flight and he offered us a reasonable solution that left us very satisfied.
I recommend this flat without any hesitation and would choose it again for my next stay in Bs As.