Location is good. It's not very far from the very heart of old Florence, and Karin is very nice. She welcomed us, gave us keys, and even provided a map with a suggested walking route and recommendations for places and restaurants. The place is taken care of and is very clean. There is even a small but equipped kitchen, and you can use it if you want.
There are a couple of reasons for my 3-star review:
* The most important reason - even though the apartment is on the 3rd floor, there is very little sound isolation. We could hear everything that was going on outside. It wasn't ideal on Sunday and Monday nights, and it was completely unbearable on Saturday night. So much noise! And we weren't warned about it. We had a hard time sleeping, even with earplugs in!
* The bedroom is in a loft, which is fine, but the ceiling is very low. I'm 178cm tall, and I had to be very careful not to bang my head. It didn't really look that way in the photos. My girlfriend is shorter, though, and did not have any problem.
* This is a small thing, but still - towels were in a horrible shape. Very old and very rough on the skin. One even had numerous holes in it.
All in all, our experience was fine. Karin is a very nice host, and the place is clean and in a very good location, but the small things and the noise were annoying.