Nacon I was referring to the actual length of the wick, it is so short that a decent pull on a sub-ohm coil would end up drying it (without sufficient wicking) and give burnt/nasty hits. The IGO-L seems like a better option for sub-ohm (not speaking from experience just what I've read) and just rebuild the Protank heads using a "normal" resistance. Or as I mentioned look at running a micro-coil in the Protank, I set one up in an old head I had and used cotton, didn't like the cottony taste, but it worked great and the un-cottony hits were fantastic.
I've decided I'm a cartotank guy, wish I hadn't just recently picked up a Protank 2 but it'll give me something to mess around with. Along with the AGA-T+ collecting dust