You should stay here. We were the first guests to stay at this property, so I'll leave a bit of an extended review.
We arrived a little before check-in, and were greeted at the door by Irina, Vasily's wife. She gave us a tour of the apartment, and described a bit of artistic intent behind what is obviously a unique home. She even had a bottle of cold water waiting for us, which was appreciated on a hot day.
As evident from the pictures, the unit is amazing. The apartment is located on the top floor of a multi-unit building. While the building appears to be undergoing some renovations, the unit is flawless. Vasily has gone to great lengths to decorate the place in the baroque style with lavish furnishings and art on all the walls. It was evident from some sketches on the exterior walls that there are plans for additional murals. In terms of the basics, the bed was extremely comfortable and the kitchen was entirely sufficient to do a bit of cooking.
Beyond the unique styling, the obvious highlight is the private terrace. You could comfortably host a party with 40-50 guests, though I think that might be against house rules. There are multiple seating areas. Some are thoughtfully shaded; others are out in the open with unbelievable views of the Duomo. Relaxing with a glass of wine and some cheese on that terrace was a highlight of our vacation.
It's probably obvious from the map, but the location can't be beat. You're less than one block from the Duomo and a short walk from the Acadmia Museum (which houses Michelangelo's David), the Uffizi Gallery (more art), and the Ponte Vecchio.
Overall, this is an awesome place to stay in Florence.