Just an update on how my Armadillos (700x23) are doing.
As previously mentioned, my first Armadillo which I put on the rear got destroyed by something that just sliced the thing, but I consider that to be a fluke as I've never had any tire get any kind of serious cut, let alone one that destroyed the tire. It had 560 miles on it. I might point out that my front tire (Conti Grand Prix 4-season), which got far fewer flats than the Conti I used to have on the rear, had two flats turing that period.
I then put Armadillos on front and rear and have just passed the 900 mile mark. I did get a flat from a big staple after 143 miles. I also consider that to be a exception because it was only the second time I've had a staple problem in over 7000 miles of riding on various tires.
Since then, no flats. Twice I have carefully gone over the tires and have found about a dozen pieces of glass imbedded in the tread (just like the ones that caused me flats in the past), but not going through the protective layers. Since I've only checked twice, I'm sure at least some of them had a lot of time to dig in further, if they could, so I'm pleased so far. In the history of my tire flats, almost all of the ones where I could find the cause, it was from glass.