I've got a Mercian 853 Pro Lugless, which I had custom built in 2003, and which has carried me coast to coast across the Pyrenees four times. It has never let me down - indeed it has never even had a puncture! ( famous last words )
I first heard about Mercian from a close friend of mine called Justin after I had a miserable tour of the Alps on a bike which didn't fit and was under geared. I duly went to Derby, was very well looked after by John Eley, and have never regretted my decision. Another friend of mine liked the bike so much, he went and bought himself a virtually identical bike to do the Raid Pyreneen with me!