There are probably 2 types of people who beleive that the piston is light years above the DI: those who were in the service, and had negligent armorors and/or leaders who passed the blame off on the user for not getting their gun white glove clean before firing, and those who purchased a DI that was either built improperly, or had defective parts. I have been at the butt end of both scenarios, and I feel the pain. However, replacing a bottom of the barrel DI with a bottom of the barrel piston is just swapping one set of problems for another. There are companies like HK and POF who make the top of the line piston systems which make the concept attractive, and they show their AR type rifles shooting from underwater, after pulling them out of the sand, etc, and there are the bottom feeders like Vulcan/Blackthorne which make guns that you better be wearing ballistic protection if you shoot, whether it be piston or DI. My point is crap is crap, whether it be DI or piston.