Location, location, location! This apartment was in a great location, walking distance to all of the major attractions in the heart of ancient Rome. Easy access to Colosseum, Roman Forum, etc. Good bus connections to any number of other places as well, if you don't feel like walking. Host was great, very responsive, and made checking in super easy. That's the most important part of the whole thing in my opinion, so if that is handled well it's a huge bonus. Host also went above and beyond the call of duty for us- she agreed to receive a package I had to have sent to Rome, baked us a breakfast tort, and did some other special things to make our stay better.