COMPARATIVE THOUGHTS
jski3:
As others have pointed out, nickle cases are more brittle, so when belling the case mouths in reloading, I try to put as little a flare on them as possible. Having done that, I still get some that split full length at every loading just from age.
How long they'll last also has to do with how "hot" you'll load them. Mild velocities will make them last longer.
Upside is that they're easier to spot on the ground, fired from a semi-auto, than brass-brass. I only use nickle .45 ACP, when shooting IPSC with a semi-auto. Several of my shooting friends give me their nickle cases, because of their relatively short life.
If I had to buy cases, I wouldn't get any nickle plated even if they were the same price.
Probably a pretty rare situation, but a rifle I had relined had such a tight chamber, nickle cases even full length sized, wouldn't chamber whereas regular brass would.
Good luck, stay safe when reloading, have a good time!
Hank M.