You can't beat that view. I've been to Florence 53 times for work and never had a view like it. Terrace is worth any money for the inspiring view, watching the people on the Ponte Santo Spirito at sunset and listening to music drifting over from the Ponte Vecchio. Short walk from a great supermarket Sapori e Dintorni across the Ponte V, with loads of choice and even great Vegan and Veg options.
Great location means you can come and go, and not feel the need to go out all day, and there's easily enough space for 4. Stairs get easier after a day but worth it to be at rooftop level. Apartment is not huge but it's simple functional and clean and everything worked just fine. Guido is just what you need in a host, helpful and friendly. Grazie mille!