Great location - an easy walk across either of a couple of bridges and you are right in the middle of Florence.
It's a walk-up. There are a lot of steep, close stairs to get up to the top floor where the apartment is located. This was no problem for us as we just lugged the bags up the stairs; however, if you weren't as mobile for whatever reason (age, disability, kids, etc.) that might be an issue.
The apartment is very clean and sleek in its decor, as it had only been renovated fairly recently when we stayed there in mid-2014.
Right around the corner is a local piazza with restaurants and an open area, so the location feels more like a local place rather than a tourist hangout, which we liked.
An espresso machine with sachets provided was a nice touch, and having washing facilites was handy being later in our trip.
Best feature = location, location, location.