The good: The location is fantastic! Very easy walk to the pantheon, market, bus stop, etc. The apartment itself is cute and looked just like the photos on air bnb. The living area was bright and spacious, and the kitchen was well equipped. No microwave though, so don't plan on reheating your leftovers. There were a few small issues, but overall we loved the apartment.
the bad: The Internet barely works as the wireless router is in another apartment. Be aware that Christian does not turn on the a/c until late June. If your visiting in may or june you might be hot, especially at night because you can't keep the windows open, too much noise from the street. We were provided with a fan though, so it wasn't too bad. It was a little tricky to shower.. One shower head was on a sliding bar but wouldn't stay up so you have to duck down a bit to get under it. The other bathroom has a tub with shower head attachment, but there was no where to mount the shower head. Well actually there is a place to mount it, but the hose doesn't reach!
Overall the apartment was great. I'd definitely recommend it if you want to be in a great location.