I have essentially the same tire, but 38mm 700C (Barlow Pass). These do very well on gravel and are superb on pavement. They are the extra light/most fragile version, but I have not had any problems with flats. I also have 55mm 700C Antelope Pass tires, which are the endurance plus version. I've only put a few miles on these on a touring bike, but they seem to be no worse on road than the Barlow Pass tires, and the transition to off-road (course, irregular gravel) is almost unnoticeable.
My 38mm slicks do slide around a bit on steep climbs, but not enough to be concerned with them. Having said that, for really demanding rides, I use the treaded version (Steilacoom), and they handle almost everything, with only a minimal on-road penalty (they are more sluggish hill-climbing on paved roads vs. the Barlow Pass tires).