Today I got my SmokTech Caterpillar in the mail. It is one of the 10 hole models and I have not rebuilt the coils yet (going to go to a friends house and build some in the next couple of days). I now find that my regular tanks are way to restricted on air flow (first world vapor problems, I know). I think I have been spoiled by that which is RDA goodness! To those looking to get into RDAs I would suggest the Caterpillar, you can find them most places for $10 -$15 and it has an adjustable air flow ring.