My .30-30 was decently accurate, and I never shot any cases enough to wear any out or develop a preference. It killed deer just fine, and my son still uses it. I gave him 100 fully prepped and sized RP cases with it, along with a couple of boxes of RP Core-Lokt ammo. I don’t see him wearing the cases out, it’s a deer rifle, doesn’t get shot a lot.
If I was buying cases today, I would probably look at RP, but price might dictate, I just don’t think it matters a bunch in a 1 1/2”/2” rifle that’s a tool.
I know some folks here shoot their.30-30 a lot, and that is who I would listen to.