I have had exceptional luck with my Borough CX Armadillo Elite Tires, I tossed those on my Trek 520 after the flats I was getting on my Kenda Kwests. I am still up in the air on a 26" tire for my Marin Novato though. I am thinking either the Schwalbe MP or the Specialized Nimbus Armadillo. The Armadillo Elite doesn't have the maroon sidewall the Nimbus does. I do prefer the non-maroon so that might be factored in, along with all the positive reviews on the MP.

However, I'd say stick it out with your Armadillos for a bit, they may yet surprise you, in a positive way.