Both front and rear tyres are Specialized Armadillo 700x25c, put on my Giant SCR 1.0 at the same time, around 2 years ago. They'll have done four or five thousand miles, which is respectable for a decent tyre.
The fact that the tyre has worn out isn't surprising; the front tyre has a lot of life left in it, but rear tyres get a lot more wear because of the constant driving friction they're exposed to. What is bizarre is the way that the outer rubber has just lifted off, revealing the tough webbing underneath. I've never seen this before, and my LBS guy thought it was very odd - possibly a manufacturing defect. Given how many miles the tyre's done, and that it still hadn't punctured, I think 'defect' is a bit harsh.
This has certainly not put me off buying Armadillo tyres; in fact, quite the opposite. They're super tough and seem to be simply puncture-proof.