Wow, I didn't know Bob Jackson was still in business. I always considered they as "classic" or collectors bikes. A friend of my has a Bob Jackson tandem. Sorry, non of that is particularly useful I'm sure. I have seen Mercian's on the long distance road and If I remember correctly Richard Cranium may ride one. Memory is a little fuzzy on that though. Either way, both are quality manufacturers so I think that if you spend the time to outline what you want it to do and make sure it is fitted properly for you, you'll be happy with either one.