As all of the reviews state, there is no better location than Alessandro's. Only minutes from the Vatican and seconds away from the castle. We found the walking distance to be even shorter than some of the previous comments. We were just less than 10 min from Piazza Navona/Pantheon, about 25 min from Trevi fountain, the Colosseum/Spanish steps/ Piazza Republica/Venice Sq were a bit further but not far.
The airbnb was clean, the a/c was much appreciated after a hot day and the location was the best part of all. We would stay here again for the location itself. For those staying until Sept 3, must take advantage of the river festival. We shared the apartment with 2 other rooms and they weren't a bother at all.