We stayed at Norm's flat in BA for several nights in April '13. Perfect location in San Telmo (just an entrance off the Plaza Dorrego) so a great mix of young and old, some really wonderful restaurants (Cafe San Juan and Maria Fedele), San Telmo Market, antique shops and of course, the sunday street market.
The apt is large with lots of light. The main window in the living space was amazing. It's in a wonderful old bldg and towards the middle (so not directly facing the plaza). This keeps the noise level down, but still the music from the Plaza can be loud. For us, having tango music in the air was a pleasure but that samba can kill you! Since it is an old building, some things are expected. The plumbing in the bathroom could use a little update (altho we never had problems with the water flow or temp.).
The bedroom is a loft bedroom. Kitchen is fine for quick meals and again, lots of light.
Norm is based in the US but was always available by email (with quick responses). He uses Casa San Telmo to manage the flat and they are right down the street. They are also a good source of info (before struggling with money exchange, ask them to suggest a place to change it!). Also, there is a mobile available to use while there ( ask Casa San Telmo for it).
I would definitely recommend Norms apt. San Telmo is a colorful and lively area and may not be for everyone but for us it was the only area to stay!