We went to Yassou as two families with four kids between us. We had a fabulous week!
The house itself is fantastic. You certainly have to like rustic, and we do! However, rustic in this case is clearly a conscious style/value choice, not for lack of amenities. In fact, we all agreed that this was the best-equipped rental we'd ever used, after 15 years of home rentals on both coasts.
As for details: comfortable beds, beautiful views, extremely well-equipped for all scenarios, plenty of corners to escape to for peace or adventures (the adults used the tower for quiet morning reading, the kids used it for a prolonged imaginative play story). The beach required 3 minute drive for most of us, as the road was too windy and busy for kids to bike on. We easily fit all 8 of us at the table. The one night we had two extra dinner guests, the kids ate at the kitchen counter/stools nearby.
You can tell in many ways that this house is beloved and used regularly by the family that owns it, and it makes a big difference to the feel of the place! If I could change anything, it would be the mosquitos. The owners appropriately warned us of their shared habitat with this property, and it was certainly a factor. We were able to enjoy the outside deck a little, depending on the weather. The screened porch was a necessary blessing. I don't know if their numbers are due to the time of year or the location just above the salt marsh, but I do know that they were a pain!
There are two many special things about this property to list, and it's better to discover them for yourself. Yassou is a special place!