My CZ75B has some sort of alloy frame. It ain't too bad especially compared to the steel version. I imagine that carrying all day does make a BIG difference! Especially if you have two to tote all day...Different strokes, for different folks. I prefer alloy frames on the guns I carry all day, every day especially cuz I carry two while at work. As for strength and durability, I'll wear out before the guns do.