Finally I was able to mount summer tires on my touring bike. I have Marathon Almotions standing by, and they are admittedly extremely supple and nice. However since our roads will remain coated with arrowheads some like to call pounded gravel for at least a month or more, I mounted marathon plusses. I don't know if it's the long winter with studded tires (which are actually quite supple) or something else, but the MP's aren't bad.
Sure they aren't as nice as the "road" tires on my allroad bike, but I wouldn't be the first to call them uncomfortable. In bigger bumps they could have a bit more flex (pressure dependent) but the puncture protection latex (that blue stuff you see inside) actually filters out a lot of the buzz of asphalt. I'd even go as far as to call them pretty smooth.
Also surprisingly the MP isn't actually that slow a tire according to rolling resistance testing. It's only around 10 watts less efficient that Bon Jon Pass, which is a very fast tire. But you get a lot of security for that 10 watts. My guess is that MP is as efficient as it is because of the puncture protection latex, which is really bouncy stuff.
My experience has also been that the stiff feeling of the MP is greatly lessened when the bike is loaded down with luggage.