I stayed at Giovanni's place for a whole month, so I feel I can speak on it pretty thoroughly! Overall my stay was good and I had a good experience.
The hosts:
First of all, Giovanni was great. He's super responsive, and checked in on me a couple times via message while I was staying, which I thought was really thoughtful. He also came by immediately later that day when there was an issue with the internet (which worked totally fine aside from a tiny blip because there had been a change in the service, I think—definitely shouldn't be an issue for future stays!).
The biggest thing, though, was that when I made the incredibly stupid mistake of dropping my keys down the elevator shaft, he was there in 20 minutes to let me in. So, so nice. That was an incredibly embarrassing and annoying thing to have happen while staying at an Airbnb, and he was super prompt and nice about it, which was so appreciated. Overall, one of the nicest hosts I've had.
The space:
The Airbnb is exactly as described and as it appears in the pictures. I thought it seemed a tiny bit smaller than I expected, but maybe that's just me. It's totally serviceable, even for a longer stay like mine.
The location:
So...the location isn't the best. If you don't mind taking transit and are okay with being fairly removed from central Florence, or if you want to be able to use a car and plan to drive a lot to explore the region, it's a perfect fit and you'll enjoy the space just fine. It's right by a grocery store, there's a park with a fenced dog area nearby, etc. The neighborhood is super quiet and feels very safe.
So when I say "not the best," there's absolutely nothing *wrong* with the neighborhood—it's just not especially exciting or convenient. It's very suburban, and very removed. There aren't really many restaurants or anything much to do nearby. I definitely felt like I had to "go into town" when I wanted to explore Florence—it felt like an event, rather than being able to just pop of of your door and experience the city. I walked to central Florence several times, but it's about a 45 minute walk, and not a particularly scenic or pleasant one. All that said, there's a bus stop about 2 blocks away for the 23 bus that goes directly into central Florence, as well as the Ponte All'asse tram stop which is about a 10 minute walk—both of which run very often. So it's not as though it's a huge pain to get to the center of things—but it's definitely not the type of location where you can just walk out of your door and find cute restaurants, bars, or anything particularly noteworthy. So I guess I'd say just make sure you're okay with being pretty far outside of the center of Florence.
Overall, I had a good experience—the apartment met my needs and the hosts were lovely and helpful. If the location works for you and you don't mind being a bit away from the center of things, I'd definitely recommend it.