I have been using Mr Tuffy for years now.
Even my Panaracer Pasela TG's were getting flats pretty often. Threw in some Mr Tuffys and haven't flatted since. I ran over a huge brad the other day. Went through the tire but looks like it got deflected by the tuffy as it exited the side wall.
You can run a kevlar tire like the Panaracer TG or Conti Gator Skins and add in the tire liners and still have less weight (and arguably more protection) than the schwalbe marthons. Those suckers are heavy!