With my Ti (.35-.45 ohm)build on the NEBOX, which is very simular to the build I use in the Cthulhu, I set it at 400F and 40 watts, but it seems to settle at 18-20watts while I am vaping it on the NEBOX. My D2 and VTC mini I have to set to Max (580+) on the Temp and 30watts/joules and it seems to settle in the 20 - 25 watt/joule range while I am vaping it. I think the curves on the VTC and D2 are not as hot as they should be.
What I am trying to get to with that rambling explanation is that I guess I require a bit more wicking due to the higher wattages I am running. The factory coils on the NEBOX (SSOCC Ni200 .15 ohm coils) require nearly the same wattage, but seem to be a bit cooler vape and don't completely vaporize the liquid, but wick lick a beast! I have not used the standard (wattage) coils.