We stayed here for a week with family in September and it was absolutely fantastic. The house it self is amazing - five great sized en suite rooms, the kitchen was huge and really well designed (which was good as it becomes a focal point for everyone getting stuck into their inner Italian chef). Great verandah overlooking a beautiful Umbrian valley as well as a large lounge and dining room too. The garden is really big and child friendly (with a playground) and of course the lovely heated pool which was in constant use
The house is very well kitted out and ideal for kids. Anna (the owner) has thought of everything - from kids gates to travel cots to baby monitors and a buggy. Means we didn't have to bring anything which made for a much easier trip.
Montone itself is real postcard Italy. Beautiful scenery surrounds the hilltop town (which is a nice walk from the house) with fantastic little restaurants and cafes (and a bakery which became our home every morning - one of the best we've experienced in a few trips to Italy)
Make sure that you get some of the local chefs to come in for a night or two to cook at the house as they're incredibly talented and make for really cool evening.
My only gripe is I wished we had stayed another week! We'll certainly be heading back to this amazing house and couldn't recommend it enough.