Maybe that's the problem, I don't want a slower heat up time. I am using to pulling out my Persei and getting vapor right away. Seems like 5 seconds of nothing at first. The 3.7 is usable and tasty just slow to fire up and get the job done. 7.4 for either coil is way too hot even with a pulse. Without the iris or core you cannot dial it in properly IMO. Since the iris doesn't work, I'm sol.
the vapor produced at 3.7v is instant with the dual coils. There is no heat up time specially with the Persei.
Plus with the new iris on the horizon you are not since we will still honor the trade in program for the iris for the new one.