We were very happy with the apartment in Santo Spirito. It was clean and spacious and was located in a good neighbourhood with good restaurants and within walking distance to the centre of Florence.
The only problem we had which I hope will be rectified so that future visitors do not have the same experience was a disturbance in the upstairs apartment which would be described as a domestic argument.
A couple of other points which I hope will be helpful would be to have two more coffee/tea mugs available, there was only one, and more toilet paper supplied. There were three of us and only two small toilet rolls available. They weren't sufficient for our needs.
I hope you find this helpful and consider it constructive critiscism. We did enjoy our stay at Santo Spirito and would recommend it as a place to stay in Florence.