Not at all impressive. Indeed, the whole MHS testing protocol was lame. 6000 rounds? Really? How can you tell how durable a pistol is from just 6k rounds? If you don't shoot it until something breaks, you're doing it wrong.
I have a P320 and I actually like it pretty well. I got it mostly for ergonomics, it simply fits me better than any Glock or M&P. And the trigger is OK.
But I'll be the first to tell you a P320 is not a "proven" gun, and I would suggest that the military testing was grossly inadequate to say the P320 is "proven."
Recall that the Beretta and the 226 went through like 25k rounds or something-- MUCH longer test. Ultimately the Beretta won by much lower cost. As did the Sig P320 this time around.
If I was still wearing the uniform, I'd be sure to carry a spare FCG for a P320 if it was my issue sidearm, assuming you could get other parts in country.
I have a sneaking suspicion that the whole MHS program will be viewed years from now as an epic, colossal failure.
The 6k rounds they put through them for the first batch of testing will not be the last. The intent during that phase is not to determine those types of problems. Many will be broken in the hundreds of thousands of rounds of testing to come. We're all sitting here criticizing the entire process before they've even gotten into phase two.
It's like a bunch of football fans wanting to fire the head coach for going 0-3 in the preaseason.