What media are you growing all of them on?
Nepenthes are trivial. Y'all have it good with CPs; they're not picky at all, or at least not nearly as bad as orchids.
I use diluted orchid mix (my OspEx 1.0, diluted down to 80% strength); I formulated N1 just for germinating neps, and it turns out it works as well or better than most orchid media for germination, too. I also use my P669 for germination as well- I sow everything on N1 and P669, as sometimes they'll come up on one, and not the other. I've also used Western media (WCatt formulation) for growing neps, and that does pretty well. I don't see any differences, to be honest; sometimes they do great on one medium, not so hot on another- but it's pretty flaky. The results aren't consistent at all. Most recently, I've put down two new formulations, one called Beta, and another one made with the MSU pure water formulation and some other stuff added in; too early for results from those yet.