IPV D2 with a Subtank Mini using my own ni200 or titanium build in the rba section. I do physically demanding work out in the field, and this set up can take the abuse. It is all cheap enough to where its no big deal of any of it breaks, as well. The reason I use temp control, is because I'm out in the elements in Florida quite a bit, and the heat can cause goofy things to happen. No matter how perfect I do a kanthal build, something will funk out from time to time, and temp control eliminated that problem completely.