One for the parents out there

They are just too expensive to really justify.
Babies can't go in unless they are supported and by 4 or 5 they are too heavy and should be riding their own bike!
Just buy a kid seat and then a trailer and buy yourself a new bike with the change. It'll still be cheaper.

Well they are cheaper than a car, and if I buy my mates Christiana it will be cheaper than shop price...

My daughter is 5 months old and just starting to sit up quite well which is why I was thinking now is the time to go for one of these. Initially I was thinking about bolting a car seat to the base of the boxes. I don't think a trailer is really safe enough, which is why I was looking at this style of bike.