I use to be very object when analyzing my staying.
As positive points I could mention the location (at the very heart of the city, including a view to the Brunelleschi's cupola); kitchen utensils (there are more than an average Airbnb, though do not expact for high quality); the offer of basic products as salt, olive oil, fruits and the like; and a hot shower (though unnecessary very tiny box).
As negative points I point out the internet (for a long period I could only connect one gadget per time, for no apparent reason, without mentioning speed); very tiny and vertical stairs (if you have have heavy luggages that could be a problem for check in and check out); heating (the highest temperature reached within the apartment was 17 Celsius degree, which means that one has to use coats if you are here during the winter); very few sockets; mold in the bedroom (if you are allergic); no blocking for natural lights (though I didn't have problems for sleeping); there is a television that actually do not work (if you are planning to watch something); and finally ask for precise address because the market has different numbers for the same building and the floor is not favorable for luggages.