Gamera The eGo batteries look a lot bigger but once you get them in your hand, they feel perfect. They put out lots of power and you can also use them with LR (low resistance) cartomizers so they pump out lots of vapor and great throat hit and taste. It's all I use, except I also have a larger NOEGO with an 18650 battery. LR works best for me. It's sorta like a high voltage vape. You will enjoy using 510 batteries with SR (standard resistance) cartomizers but you'll love eGo batteries with LR cartomizers. IMO