Hello all, I'm new to the site and upon reading all the helpful posts I decided to switch from my Choice SS no. 7. It was a tough choice between the Ego and the 510. Now since they are compatible, and the Ego is a tad larger, I bought the 510 and an Ego battery as an extra, along with some extra atty's and carbomizers. Im not a heavy vaper and bought the Ego battery to throw on when I go out for a drink or four and will need the extra battery life and performance. Was this a smart choice or should I have bought the Ego to begin with. Thanks for the help.