Absolutely spectacular location and an unusually spacious flat in Trastevere. Walk out the door and you're in the heart of wonderful restaurants, bars, and things to see, close to public transit, walking distance of virtually all major attractions in Rome.
Massimo is highly responsive to messages, email, and WhatsApp. Extremely helpful in arranging airport transfers, in providing detailed written instructions on many features of the flat, the neighborhood, Rome, and local customs.
The piano in the living room was a nice surprise. When we arrived, the check in by an associate (Massimo was out of town) was very slow and offputting, and we found many items in disrepair. But Massimo had a handyman there within an hour to fix the most immediate/essential items (broken legs on two beds). The fellow came back the next day to fix others, and once more later in the week to tinker with the internet connection when it started going out for extended periods. So he is highly responsive and quick to fix problems that arise. Unfortunately, 3 of the 4 bedroom air conditioners were not working - apparently, an electrical storm a few days earlier damaged them and the replacement parts had to be ordered -- and they weren't repaired within the week we spent there. Hopefully/presumably those are now fixed, as the weather gets hotter. We lucked out that it didn't get too hot while we there. (And Massimo graciously offered us the use of a smaller apartment where the AC was working; but we didn't want to divide up our family so declined his kind invitation.) The wifi signal is very weak in the back bedroom (I advised Massimo to get a router extended, so perhaps that's already solved) and the service was occasionally unreliable (welcome to Italy ... get off wifi and go enjoy the food and sights!).
One caution, the apartment is on the third floor, with no lift. So those with mobility issues might want to avoid this place. The six of us (healthy adults ages 22-58) had no difficulty.
This place is tough to beat for location and host responsiveness. But based on our experience, travelers who put a high premium on maintenance/upkeep and might be put off by small inconveniences might prefer elsewhere. We enjoyed it and would be happy to return.