I stayed for 3 nights in Mauro's lovely apartment in November, and had a great experience. Whilst I did not get to meet Mauro as I was going around etc, he was very available and provided suggestions of things to do and see etc by email, and checked that I had settled in etc.
The room was lovely, exactly as described, and the area was perfect, 10 to 12 minutes walk to Santa Maria Novella.
I did not expect that there to be a kitchen- I don't think the listing made this clear- so that was a nice plus. Have already recommended this place to friends and will be my first choice when I am back in Florence.