Update: EVOD heads are the way to go on the ProTank (IMHO). I got the 1.8 ohms and they are ideal for my VV/VW device (although it doesn't matter much ohms wise) and my K100 mech/mod with an EVOD (big difference ohms wise). Tighter draw (but not too tight), not as much gurgling and popping, no leaking issues, and the flavor seems to come through better. I kept playing with the wattage and found that 5.5 to 6.0 watts in my VV/VW was just right for the 100% VG juices that I am using. Voltage x Voltage / Ohms (or 3.2 v x 3.2 v divided by 1.8 ohms = 5.7 watts). I tend to want the flavor more than a lot of heat (BCC's won't give you much heat unless you crank it and then you get a burnt taste, at least with the 100% VG smoke juices that I use). Plenty of vapor and flavor at this setting for me. I am happy with the end result.