As it suits me actually. I just got done re-coiling my KFL; it had a 1 ohm 3 strand twisted coil that was working great, but my SVD wouldn't fire it and the KFL looks great on that mod, so...
I change 'em in my PT2's as they get damaged by re-wicking. Same with the dripper, although I have had the same coils in that going on a month now. If I get bored. If I see something new and shiny on YouTube, etc., etc.