I've had multiple Marathon Supreme tires succumbed to gashes. I don't consider them a touring tire. More like a commuting tire at best.
My wife and I use Supremes and have fair luck with them. I also use the basic Marathon which I think is more durable.
This happened the first day I rode on it. There was a lot of debris in the road. It made it home with a boot. The sidewalls are the Supreme's weak point. It is a moot point because Schwalbe does not make them anymore.
