Been just 2 years now that I've owned and been shooting my 2 MP 9's (a compact and a FS); and have roughly 2700 rounds total thru both. That total is near all 115fmj at the range, and probably split between Blazer Brass and Remington UMC. Never had any issues with either, tend to buy and use whatever i get on sale that month. Can't really say if one is dirtier or less accurate than the other based on how i use them, figure i kind of expect a gun i'm shooting to get a bit dirty after 1-200 rounds thru it. And I've never had a cleaning session that took longer based on ammo used. So i'll gladly continue to buy it.