I purchased an Echelon 4.0 c several months ago. It shoots well, and I have experienced no failures after 2200 rounds. More importantly, the medium grip module that came with the firearm was entirely too small for my hands. After replacing it with the large grip module, my groups are significantly tighter, and the pistol is simply much more comfortable to shoot. This firearm is my EDC, and it has just become better after changing the grip module. Anyone else with similar experiences?