joneant: "having ridden both a BJ and a Mercian"
Have you owned both a BJ and a Mercian, or just tried both. Did you ride a BJ for a while and then "upgrade" to a Mercian, if so how long did you ride the BJ for?
I only ask as I am also getting kind of interested in both and want to hear an experienced user of both's opinion.
If you have only tried both, then was the difference that noticeable?