We will be spending two extra nights in Florence and are thinking of staying near the center of the city. Does anyone have any recc. for hotels?
You might want to post this again under "Destination Q&A: Italy" on this forum -- left side of the entry page. You'll probably get more responses than here. This topic is reviews of places where people have stayed -- so you might get some ideas from reading other posts here.
What do you mean by near the city centre? Florence is small, so either you are in the centre ( which goes from Station SMN to Oltrarno or Santa Croce)
You said two extra nights, why not remain where you are already booked?
How many people are you? What are your dates and how much are you willing to pay?