I spent some great days with Marcos in Buenos Aires. The place is really beautiful, bright, has lots of sunny outdoor space in the patio and on the terrace and a nice neighborhood with lots of restaurants and bars nearby.
Marcos is a perfect host: easy-going, well-organized and absolutely reliable. It's great to chat with him and he will provide you with best inside information and tips of Buenos Aires (you will find loads of them already well-prepared in your room).
I can highly recommend to stay with him.