The apartment is in a great location, that is walking distance from the main sights while still fairly quiet. There some fantastic restaurants and bars just a minutes walk away.
The space is difficult to describe. The building is old, and the decor is quirky and charming. It's a unique experience. We loved it, but as others have mentioned maybe not the best if you have mobility problems.
Walter is a superb host, and his wife is very friendly and helpful. We'd be happy to stay again, when we next get back to Florence.