This is a wonderful place - the week we spent there was everything and more we'd hoped for. Francesca made sure we had everything we needed, and is a very experienced but welcoming host - there are lots of very helpful details. Swimming towels, children's inflatables, mosquitoes spays and spirals - it felt very generous. The bed rooms are very comfortable, the kitchen great. The additional electricity cost is very reasonable and on the whole thanks to the fans and bug nets on the windows, we did not use the air con. we were a family of 12 with kids of various ages and no car. The public transport is great, the local area is interesting and this is a perfect city break combining a private villa with city cultural access.
With regard to Florence the one tip I would make is that the Firenze Card is not really v helpful - you still queue and the 3 day time period limits you to what you can actually see in that time so we probably didn't get the value we'd hoped out of that.
Anyway have no doubt - this place is really great value for a large party - thank you Francesca.