Thanks - we just have one kid, but he and his friends seem to love it.
My missus can't drive, but we're not quite car free. We sold our car after we'd had the brown one (Fietsfabriek 995) for a while, and hadn't used the car is about 4 months, but we got given another car by her parents. The car only gets used for trips to see them, or if we're ill. In the last week, we've all had flu, so we've used in a few times on local trips, which we wouldn't do normally.. We got the second one (Bakfiets.nl Cargobike) in case we have another child and need to share the school run, but mainly because it came up on ebay at an amazing price. It's nicer than my Kona Kileaua for commuting.
If anyone fancies a go... it can handle nearly 20st in the front. This is a postdoc who didn't mind being ferried around Cambridge when he came to do a seminar.