Not long ago it seemed like about half of the regulars on this forum were using Marathon Plus tires. I mounted a set on my wife's bike because she wanted to do everything possible to avoid flats. She didn't ride it enough for me to have feedback. It's a still and heavy tire. I wouldn't use it.

I do have 700x32 Marathon Supremes on my primary commuter. I think they're a great balance of fast, durable, and puncture resistant (price being the obvious place where you make a trade-off). I've gotten significantly more miles out of them than I do from a pure road tire. I couldn't tell you how many more exactly. I had a set of 700x35s that I gave up on after ~3500 miles because I had a run of frequent flats, but I kept them because the tread still looked good and have had no problems with them in limited use on a 'B' bike. My current 700x32s are at 3300 miles. I had five punctures between 1400 and 2300 miles and almost gave up on them, but I kept using them and haven't had a flat in over 1000 miles. Apparently, I need to re-think my theory that a tire is worn out when it starts getting frequent flats.

The Marathon Supremes aren't nearly as supple as a "race" tire like the Conti GP 4000 or even the Conti GP 4 Seasons, but they don't feel terrible on the road.