I have been running a set of 26 x 2" Marathon Supremes on my primary bike for the past year. I have about 2000 miles on them with zero problems. They replaced a set of plain Marathons and I noticed a significant improvment in the ride and my speed went up by a miles per hour or so. I found that they had even less traction in loose gravel or mud that I run into once in while compared to the plain Marathons.

So in summary, as long as I don't have a mud puddle or small loose gravel to ride through, they have been the best tires I have used so far.