I'd have to say I would go a bit more than two mags full without failures before I'd feel extremely comfortable. Ideally, about 200 rds without any failures is what is recommended by firearmstactical.com and elsewhere. But despite the fact that I probably have never gone more than 50 rds without failure so far, I still carry the little beast.
Should it jam when the chips are down, I do have a backup plan, courtesy of Ben Jabituya, in the movie "Short Circuit."
"I don't know about you, but I plan to scream, and run!"

Albert