Simo's apartment is in a great location, steps away from Palazzo Barberini, and a very short walk to the Metro. It's a very big place, with plenty of space to hang out and relax after a long day of touring Rome. The bed is fairly comfortable, and it has all the amenities you'd want: wifi, washing machine, dish washer, air conditioning that actually works, tv's, etc. It's definitely one of the more unique Airbnb's I've ever stayed in, largely in a good way.
There are two things preventing me from giving it a 5 star review: First, as soon as we walked in the apartment we noticed a strong musty smell that stayed there throughout our stay. We mitigated it by opening the window on the upper floor, but the apartment was humid and damp the whole time. The second thing was that there wasn't any toilet paper. It wasn't a big deal, because we had already bought a few rolls of toilet paper because an earlier Airbnb also didn't have toilet paper, but to me that's a big oversight.