I have a Joye 510 and am considering switching to an EGO. The EGO uses the same cartos and attys as the 510 - Right? If that is true the only difference would be the EGO batteries and how long they last - Right? Why than wouldn't I just buy 2 EGO batteries and than I would have basically an EGO ???? with the EGO batteries wouldn't I still buy the exact same supplies as when I used the 510? Am I missing something - Confused as all get out !!!!! Please help! Thanks