The PM and CM Kahrs are indeed the same size. The basic differences are the PM has a polygonal rifled barrel, dovetailed front sight, machined slide stop lever, roll marking on the slide and comes standard with a second magazine. The CM has a conventional rifled barrel, pinned front sight, MIM slide stop lever, simple engraving on the slide and comes standard with one magazine. The features of the Shield probably falls in between both of the Kahrs. Quality is subjective. I've owned and confidently carried a PM9 for more than ten years. That statement speaks for itself on my impression of it. I've only had the Shield for about a month, but preliminarily believe it's going to give the PM9 a run for its money.