We had a great time in Andrea's apartments and would definitely return. In order to be a thorough review, I will mention both Pros and Cons, starting with the few Cons, which aren't even that bad. First, the bed was really firm, but ultimately I ended up sleeping just fine anyway. The shower is extremely small (like elbows touch both walls at the same time) but manageable and very clean. The WiFi is slow, but most people will probably use their phones anyway, and it would have been nice if there were extra pillows but these weren't offered or mentioned to us. Also, I'm not sure if it's mentioned in the listing but there are 2.5 flights of stairs to the unit, which could be an issue if you have mobility problems. Andrea was a perfect host and helped us carry our heavy luggage up the stairs when we arrived, though.
Now, the Pros. The unit was spotlessly cleaned, which I especially appreciated in the bathroom because most Roman bathrooms are pretty bad. Andrea's housekeeper Maria also cleans and makes your bed each day. There's much appreciated air conditioning in the bedroom, and the views from the living room or the semi-private patio are lovely and it's SO tranquil and quiet at night. The area felt safe, even in the dark, and you can literally see the Coliseum from the front door but are still perfectly removed from the noise and tourists when you want to relax at night.
Andrea was a great host. He was waiting on the curb for us when we arrived (and we saw him waiting for another group the next night very late), always answered messages quickly, and walked us through a map when we arrived that he leaves with you, describing where to go, how to get there, and a list of favourite restaurants (many of which we loved!)
Overall, we would be happy to stay with Andrea again, he made our first Euro stop very pleasurable!