The place is noisy to the point it makes it difficult to sleep for somebody with a light sleep.
Basically it's near a traffic light in a busy road of the city center, so you can hear cars and motorcycles braking and accelerating from early in the morning until around midnight when it decreases a bit.
If you're coming in Florence for visiting, there is good chances that you will sleep late so it might not be a big issue, however you will wake up early. If like me you're coming to Florence for work and need to sleep early, just pick another accommodation.
On the bright side, the place is clean and convenient despite its tininess, and the host is very nice.