Our overall experience was excellent, thanks in large part to our hosts (great people).
The location of our stay made nearly everything in Florence walkable, including the 'David' museum directly across the street. The place was very clean and just what we were looking for in terms of basic amenities (e.g., towels, teas, iron, hairdryer, etc.).
The only issue that might have made our stay slightly better would be a quieter refrigerator (dorm-room size). My wife sleeps more soundly than me, so it didn't bother her at all, but I'm a lighter sleeper, so it was an issue given the limited time to acclimate to its sounds.