Pros:
Dario was kind to offer us a pick up from the airport (for the additional fee, of course) which is helpful if you're in the city for the first time;
apartment is in great and very lively location, everything is more or less in a walking distance;
it was spacious enough for 3 of us, but would be perfect for 2;
the atmosphere was cozy, double bed on the top was comfortable (sofa-bed, egh, not so much);
Dario was quite helpful (although in the future he should check for the exact location of the nearest supermarket or similar places, it would help his guests a lot :));
we had perfectly working wifi (until my brother reached the limit by listening to youtube at night...);
kitchen had all the basic stuff, we usually ate breakfast and dinner at home.
Cons:
since we were first Dario's guests there were some small flaws. The apartment could have been cleaner - but it was just overall dustiness, the sheets and towels were ok;
if you're more sensitive to the noise you should consider some other district or bringing ear plugs - it is quite loud during the night time. We got used to it, but still;
the air conditioner broke or something the first night (it started to leak), Dario came to fix it, but the same problem occurred again after a while. We didn't want to disturb him again and it would have been difficult to arrange a meeting since we weren't sure about our plans for each day. Anyway, the temperature got bearable so we just slept with windows open (maybe that's why there was so much noise...).
Overall, a good stay. Best wishes and thanks Dario!