The 14 round mags on my all alloy are fine. They fit and fill as if there is no change in the size from the grip to the extension. Now as for the 10 round I hated the fact that I couldn't get a full grip on it. So, I took the advice from several forums and purchased the Pearce XD extension. With a little modification with my Dremel and some polishing its turned out great. I would highly recommend purchasing the Pearce extension. You would think as much talk as there is on the 10 round mag and the lack of getting 4 fingers on it, CZ would come out with an extension so, we wouldn't have to do the modifications ourselves. But for $15 or so, it's worth it..