Great visit to Florence, traveling with wife. Large roomy loft+living area+mini kitchen, with big main bed and high ceiling overlooking santo spirito piazza. Classic old school Italian feel. Very comfortable with 2. 4 would be fine (although not totally private), and 6 would be possible but maybe tight.
Possibly best location in city, away from biggest crowds (although impossible to avoid tourists unless staying in the countryside), and right next to great restaurants at reasonable prices (osteria santo spirito for truffle gnocchi, Gusta Pizza, Santa Trinita for gelato). Easy check in / check out. Appreciated the fresh fruit for tasty breakfast on the go or watching the piazza crowd.