The 1BR are great!!!!! We've stayed in them in OKW and BW, seen them in WLV. haven't seen the BC yet, but I am sure they are as nice as what we have seen!
You have almost a master suite type area, with a large bedroom with a king size bed, a dressing area that also has a jacuzzi tub and a sink. The closet is in this area. This attaches to the bathroom, which contains the shower stall, toilet, and another sink...the bathroom is very roomy. There is a TV in the MBR as well. There is a second door leading into the bathroom from the hall, and as you walk out that door, you walk through a laundry area, and then into the main hall which leads into the kitchen/living room area. There is a queen size pull out couch, which my friend (who has slept there) says is very comfortable. There is also a loveseat and a nice armchair. The kitchen is sort of galley style, and there is an island in the center of the room, making it sort of a great room type area,in combination with the living room.There is a table which seats 4. The kitchen comes fully stocked with dishes,utensils,pots/pans etc.There is a TV in the living room area, in the cabinet under the island. There are doors leading out to your balcony. All in all a 1BR would be a good size for your family. The kids could either sleep in the queen size pullout couch or you can leave the couches closed and they could each take one. The pullout couch is a 3 cushion couch when closed. The loveseat is a 2 cushion couch. I have known some DVCers to bring a blow up mattress, if for some reason they didn't want siblings in the same bed. There is plenty of floor space to do that.