wally, I have original mags from the very early 90's that came out of the box working as well as a magazine can. A couple I had hard chromed and they have been loaded since about '91. Dumped a couple times a year and refilled with premium. Nothing has been done to them. I have a couple more from that time period that see all of the range duty and so on. A conservative guess would be 25K rounds through each one at least, several P14's have lived with me but the mags stay. I have not replaced a mag spring, a follower or anything else. A couple have gotten stepped on or something and needed tweaked over the years, but all parts are original. They run flawlessly. Ammo has been mostly full power 230, with quite a few 200 SWC mixed in.
The only mag springs I have replaced have been in magazines with extension bases. The factory springs flat will not work, nor will any other aftermarket spring that isn't longer than stock by at least 3/4" and stock weight or better. Wolf springs have been used in most of these, and they suck. They don't last. I am trying some IMSI now but time will tell. The Wolf extended +10 springs lasted less than one year, maybe 10K rounds per mag at most and I was very disappointed.
Current production mags had a few nose up jams for me right out of the box in a gun that runs absolutely 100%. The cause in all of mine were the feed lips releasing the round early. Closing down the feed lips just forward of the base of a seated round out to about halfway down a seated round is all it takes to get rid of it. Once the extractor has purchase on the rim the round should release, not a bit sooner. Those new production mags have been flawless since tuning the lips. Ooops, I forgot that one didn't want to drop free, but a little therapy had that one running just fine too.
I don't find tuning magazines to be a problem. They are the heart of a good gun, without them it won't run no matter what. We spend hundreds and even thousands on guns but balk at the cost of magazines and giving them a little tuning to ensure they run right. I figure if I spend a bit of money on a good gun and then modify it to suit me just right that I can't complain about making the magazines just right and spending a little money along the way.
I have a harder time picking on magazines for the shorter than 5" guns, those guns are a whole other story with their own list of potential problems.