If I may chime in here?
Please, if you are going to get a 510, get the Ego. The battery life is tremendously longer and you will have no need for a PCC (charger on the go). With 2 Ego bats charged you will make it all day and then some.
I have big bat mods, Chameleon, Precise, Little Sister, Bottom Fed juice Boxes and the like. I love them all. For a standard e-cig, the Ego battery is the longest running charge to date.
I think I might enjoy having the PPC, because I mainly vape while I drive, and I have a USB charger in my car. I figure charging the pack while I drive I will always have a good battery, also I will have a receptacle to carry the equipment with me instead of keeping the e-cig in my pocket. The smaller size of the 510 is also appealing, easier to handle on the go. Unfortunately I don't want the kids to see me "smoking", even though I'm vaping that's more than I want to explain to 7,8, and 10 year olds. So I appreciate the advice, but the 510 seems like a better choice for me right now.