As is the norm I agree with Vuitton.
The FS in Florence really is an exceptional property. You will need a cab to get to anywhere but the grounds, pool and service more than make up for it. Not cheap mind you (their quote for an airport transfer was beyond funny) but I had a fantastic weekend there for a wedding.
Naples is basically a wheelie-bin. Avoid. At all costs.
Capri is a great shout - truly magical island. The JK Place is a stunning property but is actually in Ancapri so isn't walking distance to the main action. I recommend the Scalinatella
www.scalinatella.com. Great views and service although like most hotels on the island its not big. Make sure you go to The Lemon Tree for dinner.
Actually the JK Place is all the way down in the Marina Grande area and not in Ana Capri. THe Capri Palace is in Ana Capri