The place was just as advertised - 1 minute walking to Fontana di Trevi, 5 to 10 minutes from the Panteon or Plaza Navona, or the Spanish Steps - right in the middle of everything - huge bonus points for location.
It's in a remodeled attic, so the sleeping areas have sloped down lower sides - you need to be careful when you get up from bed or the couch, else you could hit your head in the supporting beams. This is something that's reasonably seen on the pictures - just be mindful of it. Also, it's almost 5th floor in the building and no elevator, so walking up to it may be a challenge if you need to do it more than once or twice per day. No complaints there, just mentioning it.
It's clean, has all the amenities I needed, has two comfortable queen size beds. The hosts were very flexible with my check-in (I arrived earlier before the cleaning had even started, and they let me in and gave me the keys so I could leave my luggage there and start exploring the city). The two air conditioners worked very well, which was important with the high temperatures and humidity of mid-August.
The only two things I would have wanted to see different - the entry to the balcony is literally 1 yard high (blocked by a weight-bearing beam), so you need to crouch down to get to the balcony. Probably hard to fix since that's part of the structure. The other detail - the shower box is really, really tiny - it's a square of probably 2 feet by 2 feet. Even though I am not a big guy, it felt really tight taking a shower there. If it can be replaced by a slightly bigger box (perhaps even larger by half a foot each way), it would make a huge difference. Especially since taking showers in the summer heat is a great way to cool off.
Overall, however, the experience was great, and as long as you are aware of these couple of details, I would wholeheartedly recommend and would visit again if I had to go to Rome. Cheers, and enjoy Eternal City.