Count me as another satisfied Armadillo user (700 x 25 on one bike, 700 x 28 on the other).

However, my number one strategy for avoiding flats is to stay out of the debris field at the edge of the roadway. Around here, that includes bike lanes, which are rarely swept. Cars are very efficient at sweeping all the tire-murdering crap over there. This isn't the place for endless VC debates, so I'll let it go at that.