The apartment building is very cool, safe (key card to enter), is in a great location and has an amazing rooftop deck.
The apartment has a mid-century look but is modern, so you'll get modern amenities. It's a well decorated apartment and there is room to comfortably fit 6 people. I traveled with a group of 5 and we really enjoyed the many bar options within a block from the unit. The location is close to the historic center (4 blocks or so) but far enough to where you're around tourist trap restaurants or bars.
The rooftop deck is pretty awesome. I stayed for 4 nights and I spent some time up there each of the days I was there.
Finally, Cristian was very responsive and accommodating. I would give him 5+ stars as a host. I'd recommend this apartment to my friends & family.