We thoroughly enjoyed our stay at Alessandro's apartment. Everything, from booking to check-out was great. It's really a pleasure to deal with Alessandro, he is very responsive and helpful.
The location is not very central but easily accessible by metro, bus or even on foot (though plan for 45-50 minute walk e.g. from Trastevery) but you are getting to stay in a really large and stylish apartment with enough space for everybody (well, we were only 3 but still) and two separate full baths. Besides, there is its own charm in leaving in the residential area, you get to see some locals, not only crowds of tourists.
In a word, we highly recommend Alessandro's apartment and will definitely try to stay there again when we visit Rome next time.