We highly recommend this spacious apartment, which is well-located, a block from the Piazza Santa Croce. We walked just about everywhere we wanted to go, and it was easy to catch a taxi at the piazza for places further away. The apartment is in a relatively quiet neighborhood. There's a farmacia next store and a bodega and bistro nearby. The rental company is very responsive.
When we first booked it, the apartment was listed as sleeping 8 in one place and 10 in another. We had 10 for 3 nights, which worked because we had 4 unfussy teenagers with us - the team brought in a cot as an extra place to sleep in the small 4th bedroom, and 2 of the teenagers shared the comfortable fold-out sofa in the lounge. Ten people sharing 2 bathrooms worked out fine for us. We never cooked but were able to all sit at the small table for breakfast.
During a hot June, the steps up to the 2nd floor (3rd floor for us in the US) were a bit of a challenge -- since the ceilings are high, it was more like 4 flights of stairs. The hallways were plenty cool, though, and the A/C in the apartment worked well to cool us off once we climbed. Because of the steps, I don't recommend the apartment for those with mobility issues. We figured out the washer/dryer with help from the manager - just keep in mind it doesn't dry clothes completely. The apartment has large drying rack and there's plenty of room in the center hallway to use it. It was just what we needed to keep from having to go to a laundromat.