My first day here and I am absolutely loving it. So I just wanted to know whats the difference between dual coil and single coil builds. What are the pros and cons of each and does it come down to preference? Also I was using a website that one of the experts here refereed me to, http://www.steam-engine.org/coil.asp, and when i click the option for dual coil it says that the total resistance is halved. So does that mean if I want my target at .3 ohms i need to input .6 ohms?