I'm going to buy a couple of new bikes and test them out as light tourers. Each one is obviously not purpose built to tour on, but I think they will both do reasonably well with loads less than 25lbs and a rider around 180lbs. I don't use any racks that attach to the bike frame so I have a lot of options, and anyway I need a new carbon bike and a folder to take on the T and bus.
The first is the Cervelo RS. I went through numerous "plush bikes" and considered the Pinarello Rokh, Specialized Roubaix, Cannondale Synape etc........it was a long list, but in the end the Cervelo RS has a very good reputation and history and is was one of the least expensive and least gimmicky of the bunch, not cheap, but good value.
and the second is the Tern Verge X10. I considered a Brompton, but the weird gear setup, weight, 16" wheels and poor quality of equipment on it turned (no pun intended) me off it.
Don't flame me too much, I'm not going to be going over any mountain goat paths on these, just paved roads in reasonable weather.