I know this may seem a little odd, but I asked a dealer if the sights on full size and compact XDs are the same. He said no. I'm not sure I trust his answer. I like the concept of Tru-Glow's Fiber optic sight backed up by a tritium vile. Will the sights on a 4 inch or M Factor shoot the same point of aim on a Compact XD. I do know that a CZ75 and the CZ75 Compact take deferent sights. CZ 75 sights will shoot 4 inches low if you install them on a compact CZ at close range, there for the further out you go the more pronounced the problem. Thanks for answering a new-bee's question..