We were a group of 5 adult couples. Not all had private bathroom/shower (see their description). Still, this is a huge (!) place, with plenty of big living/dining/game rooms. The kitchen is small-ish but works. The building/castle is truly amazing, you will be impressed, and the grounds are beautiful.
We were less impressed with housekeeping (just daily bed making, but no new linens all week, and fresh towels only upon request even if they were placed on the floor). Most of us weren't happy with the mattresses. A pre-stocked refridgerator for our late-pm arrival would have been nice (no such option) - that would be super helpful when arriving from long distance and have no idea where to buy what.
Now, the castle is an authentic 1000 year-old building, and while all that is really special and impressive, don't expect window screens (big bugs find their way into the bedrooms), no modern plumbing, and showers and drains are so-so. So that's the trade-off.
The location is amazing, quiet, hill-top with incredible Tuscan views - something you'll write home about! You feel like a king up there.There's a groundskeeper who's very helpful with where to go, what to see, etc.
The nearest town is ~15 min by car, with a train-station (to get into Florence), a really big grocery store, plenty of small restaurents, etc. Really everything you need is there.
Perhaps except for the bedrooms' non-biting bugs and the mattress quality, this is a spectacular place you'll not forget.