I'm currently running Specialized All Condition Armadillos and am reasonably pleased with them. They are on the heavy side but I haven't had a flat since I got them. Mine are 700c x 25 and ride harsher than the Bontrager T2 tires of the same size they replaced, but the Bontragers were nowhere near as resistant to flats, but they were just a standard road tire, not the flat resistant version. If I go with the Armadillos again when these wear out, I'll be going wider which supposedly will improve ride quality. A lot of people here recommend Continental Gatorskin tires so I may consider that route as well. The GP4000 gets a lot of press, but is more of a fast road tire than a loaded touring tire.
Bottom line: The Specialized Armadillos are as bulletproof as any tire I have ridden but are at the heavy end of the spectrum and you trade some ride quality for reliability. I'd give them a 7 out of 10.