I can't praise this hotel too highly.
The staff are absolutely fantastic. They can't do too much for you - and they are a mine of useful information. Special thanks to Monti for the restaurant recommendation!
The location is perfect: close (one minute's walk at the most) - but not too close - to the Ponte Vecchio, and in a ideal position for visiting the vast majority of the sites in this lovely city. The street, itself, is quiet, which is quite amazing, considering how busy the city can get.
The hotel is on the second floor of a tall 15th century building, accessible by small lift (there are three short flights of steps to the lift). Rooms are located on different levels. The room we were in was very spacious, with marvellous views of the river Arno. Our room had a sink and a private bathroom (only accessible with our key) down the corridor but there are other rooms with en suite bathrooms.
The breakfast buffet was good and it was served in a light room. Again, the service was excellent.
If you're going to Florence, stay at this hotel!