The Thorn bible seems to suggest that the Mercury MKIII is more suited for lightweight touring than the Nomad while the Nomad is better for heavy loaded tours……..if the Nomad does everything well then why is the Mercury made?
There's the physics (aerodynamics, rolling resistance, weight, power) which says if you keep them constant the outcome will be the same, and if you change any of them the outcome could be calculated, it would be foolish to argue any different.
Then there's the subjective stuff, I'm happy to give my opinion, I'm not at all bothered if someone has a different one! I can do everything on my Nomad, even in it's different build, that I can on my Mercury, it's a very versatile bike. My Mercury is far less versatile, I consider it to be, as it was first marketed, a Sports Tourer. It handles sharper, it makes a twisty decent that would be dull on the Nomad exciting. It feels more responsive, which in turn encourages more spirited riding. But loaded up, even within Thorn's limits, it feels flexy and less stable. Even without luggage it doesn't feel as sure footed on bad surfaces. it's more engaging to ride, which can be exactly what you want, or what you're trying to avoid. Both are comfortable in different ways, the Mercury makes average tarmac feel silky smooth, the Nomad less so but irons out larger imperfections. I feel more detached from the Nomad, sat on rather than in, which may be due to less BB drop. I'm close to the Mercury rider weight limit and riding the largest size, I'd be surprised if a smaller lighter rider didn't have a different experience, the physics are different, how much effect that has on the subjective stuff is an unknown.
The Mercury is my favorite bike to ride, yet the Nomad is my most ridden bike (That was the same way round when I had an Audax and a Raven). I'm glad I have both, but if I could only have one it would have to be the Nomad.
