While anecdotal only, I had a P226 magazine that I loaded with Hydrashocks shortly after Hurricane Andrew. I did not quite make it the twenty years as ran out of patience but a year or two ago I used it. The magazine that stayed loaded for a bit less than two decades along with the ammunition functioned fine.
If you use the magazines regularly they will let you know when the spring is weakening and if you do not use the magazines regularly the spring will not weaken very much.
I never talked to anyone who had to fire their gun who said "I wished I had the smaller gun and fewer rounds with me" Just because you find a hundred people who agree with you on the internet does not mean you're right.