Roberto and his nephew Marcelo were great hosts. They were always available for questions and restaurant recommendations. They also provided breakfast essentials, bottled water, and a bottle of wine to welcome us.
The 18th floor apartment has lots of space (our group of 5 had ample room). It's not a new building, but it has all you need in a home base. When it's clear you can see the mountains behind the city - very impressive.
One tip - it's about a 15-20 minute walk to the nearest Metro stop (Irarrázaval) so you'll want to plan your day with that in mind.