I have the prebuilt nickel coils for the Crown and I think they are fantastic. I am running them at 50 watts and 440 degrees right now as I am slowly breaking them in (not necessary - just experimenting to seeing if it extends the life at all because I use nasty juices that kill all of my coils) and it is a warm, dense vape. I generally turn it up to 70 watts 480 degrees and stay there and it is perfect.
I had the stainless coils running on TC with my Opus as well, however, the TCR from Steam Engine was off by a bit so I figured I would be better off using the nickel coils on the Crown for now.
ALSO: Has anyone else seen Rip Tripper's first look at the Vapor Shark 200? He is referencing a problem running nickel claptons and hybrid builds (either saying they are in temp mode and burning or jumping out of temp mode) which he has had on "all" his DNA200 devices (hasn't tried the VS yet though). I have the same problem, however, I figured it was my incompetence building nickel claptons or hybrid builds and not the device. Is anyone else having this problem or have a solution?