I've had Marathon Plus, mentioned above, and also their Bontrager workalikes. They're high pressure tyres which sacrifice everything to being puncture proof. They do what Schwalbe promises, being as puncture proof as it is possible for an inner-tube tyre to be, their longevity is excellent, the corner tread is useful off-road, and they're fast; but even on smooth roads their ride is harsh, and that's if you inflate to the lower limit; if you inflate to the higher limit, your hands and bum will soon buzz. I didn't regret leaving the Marathon Plus behind for Big Apples.
I would recommend Marathon Plus to those who ride the meaner streets of the city, broken glass on the verges, suchlike, maybe commuters for whom the excellent longevity might matter, but I don't think it will make much of a touring tyre, especially since there are close relatives that Schwalbe themselves consider better for touring and that experienced riders here recommend.
Andre Jute