Called Luca while we were at the Florence Airport. Waited for slightly over 15 minutes for someone to arrive downstairs (Luca's colleague came over). Check-in was fuss-free and she took some time to show us around the apartment and recommend a few attractions and restaurants.
Apartment was clean but small (not unexpected). Staircase was indeed as "funky" as shown on picture. No problems as we mainly used the sofa bed on the main level (there is a bed on the mezzanine as well).
Air-con, wifi worked well. Shower area was a bit small though. All other facilities worked fine. Multi-plug adapter was located near the sofa bed (we took some time to locate it as there were no available wall plugs to charge our devices).
Close to attractions (stone's throw away from S.M.N and the train station) and plenty of reasonably-priced restaurants nearby.
Street outside was a bit noisy at times at night, but we still slept through with not much problems.
Overall, was a good experience. Will recommend to friends who might be travelling through Florence in the future.