I've been vaping now for almost three months. I've experimented with CE4, CE4 wickless, CE5, EVOD2 (both plastic and glass), a iClear 16D, a Kangertech Pro Tank 3 with add on air flow regulator and a T3S BCC. My mods are 2 eGo 1100 mAh non VV/VW batteries and a Smoktech SID using 18650 battery. My juices are pretty straight forward tobacco flavored at 18mg. I have a cherry juice that's not so cherry, lol. I add menthol to ALL my tobacco juices to smooth out the hit a little. It works, for me. I'm not going to go into which I prefer as it matters not to this question. The question being, what is the difference between a BCC and a BDC other than one is single coil, the other dual? I'm not a cloud chaser, I am an ex-smoker, thanks to e cigs and mods. My T3S makes wonderful clouds for me, delivers a full hit loaded with flavor. It is a BCC. My Kanger PT3 makes wonderful clouds and delivers a full hit and great flavor. It is dual coil. Personally? I see no appreciable difference other than the PT3 needs a higher wattage than the T3S. Oh, and the PT3 looks wicked bad on my SID. Thought's and experienced voices on this will be profoundly appreciated! Keep on Chuffin'!