I just counted and I currently have 22 Benchmades, all but two DarkStars and one AFCK are AXIS lock knives. I've sold or gifted another 9 or 10, all but one of those AXIS as well, and my wife has another 4. I'm probably gonna jinx myself here, but in almost 10 years of inveterate fidgeting and flicking I've never broken an Omega spring. I also live in a salty Atlantic environment, but have never seen any sign of rust or corrosion on my springs or anywhere inside my knives. I do carry and use them as EDCs, working construction, around the house, and up north in our Vermont woods and fields.
One thing I've read is the recommendation to use both AXIS buttons when retracting, as that puts less strain and equal pressure on the springs, and that's my usual practice. I also take care to treat my knives like any other quality tool, avoiding wetness when possible, not getting them all full of dirt or corrosive material, as well as cleaning and drying them off when they do encounter such abuse.
Anyway, I'm glad I found this thread and feedback on various options, as I'll inevitably break a spring or two now and would much rather make my own than go to the trouble of sending a knife in for such a simple repair. In all my years as a Knife Knut I've only ever sent one in for any service, that being my son's Crooked River with a broken wood scale--graciously replaced at no charge by the good folks at Benchmade.
Edited for formatting.