Schwalbe marathons are heavy, but they also give a nice carefree ride. You just don't have to worry about the road surface at all because the tread is so thick and under the tread you have a few mm of puncture protection as well as a really sturdy sidewall.

I've tried a bunch of various tires from slicks to heavier stuff to MTB stuff and I currently have a set of vittoria voyager hypers waiting for better weather. Only the Schwalbe marathon line is able to give me the carefreeness to ride over broken glass with no worries. With the voyagers I'd worry about riding slightly rockier gravel, because the sidewall is really, really thin and the tread isn't all that thick either. Even with MTB knobbies I sometimes get a bit anxious if there's anything sharp on the road since even though the knobbies are thick, the tread under them isn't.

It's a good thing I don't care about bike weight, a few lbs here or there for total carefree is completely fine for me.