Great experience ! The flat itself is cute, very clean and welcoming. The location couldn't be better : Trastervere is the perfect neighbourhood : lots of bars and restaurants, and easy to walk to the main attractions (or rent a bike, which is super easy). Beside, even if you are in the heart of Trastevere, it's not too noisy (fortunately). Of course the terrasse is the main strengh, we spent hours there, just enjoying it, drinking coffe or wine (depending on the time).
And last but not least, Andrea is a real nice host : always available for any question, very flexible and he treated us with a bottle of wine, which is a super nice thought. Totally worth it !