On our recent Viva Italia trip there were two young couples without kids. One couple were both teachers. We had 8 kids 12 and under, and some very pleasant and well behaved 13-16 year olds. At the end of the trip, while we were saying our goodbyes, one of the couples said that they enjoyed having the kids around. Maybe they were just trying to be nice - but I think overall we all enjoyed each other's company, and the adult/kid relationships between and among families did add some very special, positive qualities to our trip.
Wow, I really miss our group!