Marco is a great person. He was very thoughtful. When we got there (9 am) he was already at the flat waiting for us. Everything was set up for us, and he has a map with places of interest marked to help you out during the days you're there, so you know where the supermarkets are, the farmacy, hospital, etc. The kitchen has everything you could need and even more.
It's a very old appartment, so you have to keep that in mind when you go there. It's only 15 minuts away from the center. If there's people outside talking loud you can hear it, but it's not in the center, so it's OK.
Marco let us leave in the afternoon the day we had to leave, because our plane left at 7 pm and we had to spend the whole day in Florence, so it was very helpful.
In summary, I recomend Marco and his apartment. We are so greatful for him.