I doubt I'm alone when I say that I replace my recoil springs pretty regular... and have a box full of striker springs/hammer springs sitting around.
I think they are supposed to have more tension than factory.
I never had a NEED to replace one, I thought, until a recent range session.
In my car I keep a Glock 29 hidden, and loaded. I don't shoot it a lot.
Last weekend, I pulled it out and when I went to Wade's and had a 50% failure rate on my reloads. The striker was hitting the primers (WW and CCI 350), but not detonating them. I replaced the striker spring with one of those Wolffs I had, and it was back to 100%.
Simple moral: Replace them every once in a while in guns that are constantly loaded with hammer/striker "cocked". I'm just glad I didn't really need it.
Tom