This apartment is tough to review because whether you love it totally depends on your priorities. Let's start with the good stuff:
The location. Oh my god, the location! Less than 1 minute from a major bus/taxi stop than runs most lines every few minutes.
Walk in the opposite direction for a couple minutes and you are standing in front of the Pantheon in a piazza full of shops and restaurants. (Don't sleep on Gelateria Della Palma & All'Antico Vinaio!) You can walk to the Colosseum in less than a half hour, and it's a walk full of piazzas and churches and restaurants.
There is a decent grocery store across the way too. That was good because the included free toiletries consisted of a half empty, upside down bottle of store brand body wash. You can imagine how not minor that is when it's 11pm the night you arrive and you have jet lag and go to take a shower and there's no shampoo. (We later found a couple of tiny plastic packets of conditioner the host seems to have borrowed from another establishment, but no shampoo or soap and certainly no extras like q tips or toothpaste.)
You will feel like a local staying here, which we loved, but the apartment is dingy. If you're squeamish, it's going to bother you. There's both a minor buildup of ancient dirt and a little bit of recent scuzz.
The local caretaker Mr. Alberto is lovely and helpful and prompt.
I would probably check out other options in the neighborhood if I returned, but in the end, I would stay here again.