My 40C to 9mm conversion has been flawless for several months now. Originally I intended to use the 9mm barrel for range use only but it easily passed my benchmarks for reliability, most notably with the 17 round mags so it's currently on my nightstand in that configuration. Now I did just find a couple of 15 round .40 mags so when I get those I will swap it back to .40 and call it good.

The OEM barrel conversion for me was the single most important reason I purchased my 40C and I have not been disappointed.