I bought two from CGW maybe six years ago for a single action only 75B with a Kadet slide. I may have swapped them at 30k rounds but kept the old one for a spare. Probably have 20k on the second one. Double action will be much, much, harder on the spring than mine. But, if you want a datapoint, mine haven't failed and I don't worry about the CGW spring at all. Even if you find someone who has had one fail, doesn't mean you shouldn't get one. Just get two or three and change them once per year in a DA/SA pistol. And get the CGW trigger pin, it is a must have.
Joe