a quick google search shows a fair number of issues spread out across the various gun forums, however based on the fact that there's probably untold thousands of these chargemasters in the field - i'm betting the 5 year failure rate is pretty low %.
my only reason for that speculation is that if it was THAT awful at sub 5 years, i cant imagine a lot of folks would want one, nor would you see them regularly praised by their owners like they seem to be.
it would be very interesting to see a study of fail rates as a % when graphed out over time, unfortunately if that kind of data even exists, the chances of it getting out 'Into the wild' if you will, are probably pretty low.