I use a buggy board every day - great for the children - not so good for me!
I put my back out a little while ago cos of the funny angle you have to walk to push the buggy when a child is on the back and your arms aren't long enough
going uphill is hard work and going downhill is a bit scary (ok if you live in a flat town I suppose!)
Apart from that they are great and certainly easier that a double in my little town with hardly any pavements!
Sarahx