I use this tire on an older 85 Schwinn Le Tour Luxe that I use for touring, since most of my touring weight is on the rear I only use this tire on the rear and use a lighter touring tire for the front. I've only put 250 miles on the tire since I got it this last month but I did learn that for a heavy tire it doesn't feel heavy on the road, it must have less rolling resistance than other tires of this weight class. I also didn't get to test the puncture resistance of the tire and hope I don't have to but I did put in a liner strip for extra precaution since I don't want to be fiddling with taking off the panniers if I were to get a flat. The tire has a built in reflective strip on the sidewall which actually works quite well when I aimed my car's headlights at it.
There is one downfall to this tire, but I didn't fault the tire for it since I was expecting the problem due to thick stiff sidewalls, and that is it's very tough to put on. I made the job a bit easier by placing the tire next to my wood stove for about two hours to get it quite warm but not hot, then with soapy water I tried to put the tire on but it was still quite tough to do the last 6 inches but I do have a couple of tools that made it a lot easier. The first tool is a set of Soma Steel Core Tire Levers, these won't snap in two when the going gets tough like all plastic ones can, the second tool is a VAR tire lever, this tool is what I used to get the last 6 inches on and it does it rather easy...but not really! but easier than using levers only.
I bought this tire based on over a hundred reviews that I read that were all positive, so I don't expect to have any issues with it either in flat protection or long tread life, or traction issues. I do touring on mostly pavement but sometimes I ride on gravel so I needed a tough rear tire. The tire I bought was NOT the Marathon Plus, it was the Original with GreenGuard, the Plus is even more puncture resistant than the one I got but quite frankly I'm not sure why someone would need that sort of the protection the Plus offers unless you were doing some sort of cross touring. My touring tires I had on the bike before the Marathon didn't flat and they were lighter, in fact I'm using the old rear tire as a spare.
Anyway choices for a touring tire for a 27 rim are very limited to just two, the one I had on before was considered a light load bearing touring tire, this Marathon is a heavier load bearing tire.
If by some chance I run into issues as the miles pile on I will report back but I seriously doubt that will happen based on all the positive reviews I've read.
Thank you for your feedback.