Hi DM,
I'm glad you are having good luck with your Norinco mags. And with that many, I'm sure they will serve you well. I'm certainly not looking to start a battle over mag preferences, but I'd just like to offer a counterpoint to your post.
To start, 6000 rounds divided by 14 mags works out to about 428 .6 rounds through each mag. That is not really enough shooting to fully break the mag in, let alone start to see some of the wear and tear issues that can crop up with cheaper mags. I would be interested in hearing you report back once each mag has 2 or 3 thousand rounds through it. Who knows, some of us may be very surprised at what we hear...
1911's, more so than other handguns, rely on the magazines as in integral part of the feeding system of the gun. The design of the mag lips, the durability and consistency of the mag spring and the design and materials used for the follower are all critically important in ensuring reliable and consistent feeding in a 1911.
The magazine controls both the feed timing and release timing which are critical to the smooth operation of a 1911. If either of these timings goes even a bit sideways (due to worn or weak mag springs, worn or faulty follower or damaged or poorly designed feed lips, just to name a few examples) you will have feed issues and stoppages with your 1911. None of which, I should point out, can be fixed by cleaning or lubing your gun.
That is why the companies that make the more expensive mags tend to go out of their way to utilize higher quality springs, stronger bodies and feed lips, and often uniquely designed followers to try and ensure consistency between the first round you ever feed through the mag and the thousandth round... Keeping in mind that no matter how good the mag is, eventually springs and followers need to be replaced. With more expensive mags, those intervals will be longer then they will be with less expensive mags.
Your choice in mags may also be influenced by how you shoot. Standing at the firing line shooting mag after mag while carefully handling your equipment is much different than shooting in "run n' gun" games such as IPSC or IDPA. mags get banged around, dropped on concrete floors, dropped in mud and filled with dirt and crud during the intense action of participating in gun games. This unavoidable abuse necessitates the use of better built gear, especially 1911 mags, that can take the punishment match after match, practice after practice, and still perform.
So while you may be absolutely thrilled with the performance of your 14 Norc mags (and I think it's great if you are happy with them!), It is important to realize that, in a 1911, good mags are every bit as important as a properly tuned extractor and a good recoil spring. I don't think that Norinco mags are "bad" as such. There are just better ones to choose form that, experience has shown me, will give me less headaches in the long run.
But of course, YMMV.
Cheers!