I have several 26650 RDAs. I love my Castor by Fog Monsterz. It is pricey, but I think it's worth every penny. With a Sleeper Coil build 24g 7/6 wraps 3mm ID => 0.3 Ohm, I'm getting huge clouds, and lots of flavor. It's my favorite RDA out of the 43 RDAs I own.