Got Low Resistance 510 Cartomizers, the hit is really good, throat hit amazing, if you get the right liquid in there, it's smooth and strong, just like a real cig. However, filling direct from the mouth can overflow easy and come out the holes in the top atomizer. I'm not sure how I feel about this because the regular 3 piece seems easier to control, with the cartomizer, you can't see if the top is dry or not, so I'm a little frustrated with it. The taste is also much less than regular 510 atomizers, but the hit makes up for it. My regular 510 atomizers could never produce such a nice hit. If you learn to fill it right, I'd say it's the best E-cig ever, or else you got dripping in mouth. Oh, and some of them have screwed up filling with the middle hole not rightly placed, being completely worthless. I had one that was messed up with the middle hole and when I sucked it was a mouthfull of liquid.