The apartment is in a great location and very close to the Duomo and all other major sights. It is nicely decorated and quite modern and the bed in the mezzanine feels very cosy. Also the bath tub is great, especially in winter when it;s cold outside. Talking about winter: unlike in many other flats or houses in Florence, the heating works perfectly in Thomas' apartment. I can definitely recommend the place for a stay in Florence, especially if you come for a holiday.
There are some minor issues: the apartment is quite dark (not a lot of daylight enters through the windows since it is on the ground floor). If you stay for a longer period (like us) this may start to bother you after a while. Also, the reception for mobile phones is very weak and the internet is quite slow.
But overall we had a great time in Thomas' apartment and can recommend it.