TJ:
Welcome aboard!
My personal response to your excellent question is that the R9 is one of the the smallest and lightest 9mm pocket pistols yet devised. It has minimal tolerances and, like the Seecamp .380, literally pushes the envelope for its caliber. To paraphrase Karl Rohrbaugh, it was designed to be "carried a lot and shot a little."
By the time I had run about 100 rounds through mine (No. 132) with no failures, I determined it to be absolutely reliable and in need of no further testing. I now shoot it only occasionally, a clip now and then, just to maintain familiarity.