That Sheldon Brown article is an old article that was written when glueless patches first came onto the scene and that article was never changed after the glueless patch companies came out with a better adhesive. If you recall, even the glueless patch companies back when they first came out said that they were temp patches only, they themselves no longer say that.

I personally don't like the cheap K-Mart or Wallyworld patches only because they are thicker then Rema's. I don't have anything against glue patches, they work great and have for years; but after I tried the glueless patches and never having a failure I was sold.

Also someone mentioned Slime tubes. I found that slime tubes on road bikes don't work because they won't seal above 60-65psi, but they work pretty good on mtb tires if you don't mind the green goo getting inside your rim.

Also I use to live in Goathead City...I use to live in the Palmdale, Lancaster area as well as Bakersfield all of which are in California and I NEVER had a goathead penetrate a Armadillo road tire not alone a mtb tire! And all I had for a tube was a ultralight racing tube and NO tire liner. Before I went with the Armadillo I had huge problems with those buggers, even going through kevlar tires with Mr Tuffys and Slime tube (that's how I found out Slime tube was useless).