Though it is a little more pricey than other rentals in Rome, you definitely get what you pay for. A single bedroom apartment with a large bed and a couch bed and a kitchen. Plenty of space to relax and live out your Roman lifestyle. The apartment stays fairly cool during the summer, which is a huge plus.
The location is also great. About a 3 minute walk from a metro stop (though you'll hardly need it); a 1 minute walk from some great restaurants (Ristorante RomAntica, Club Machiavelli); a bakery is right nextdoor. (For a treat, open your windows in the morning to the courtyard and the smell of the bakery's fresh baked goods will fill the air.. have their cornettis for breakfast!) Further, it's just a 10 minute walk to the colloseum.
We only made contact with Mario, but he was great. He was flexible to our delayed arrival and made our check-in very painless.