(it is a half bike that attaches to an adult bike)

Does anyone else have one of these? I'm considering getting one as I have a great bike but can never ride it as I always have to tag along a child. Have seen these around at the local bike shops but what to know what they are like on the roads.

Also considering the trailer attachment (pram like with seats for 2), if anyone has those, I'd love to hear any reviews!

Thanks in advance