My $.02 for what it's worth:
The EGO is a pretty good product for a reasonable price point. I like that it has the atty cover cone as it tightens up the draw, giving a pretty decent TH. Some of the other "bigger battery" models I've seen don't have this feature. I recently purchased the large EGO battery from a China supplier and have been loving it ever since. I would recommend the EGO to anyone. I started off small, though - 1 battery, 1 charger, 1 cone. I've also purchsed the HUGE EGO cartomizers, and am not thoroughly convinced with their performance. Granted, I haven't played with them long enough to completely figure out the trick of re-filling them. Mostly, i've been using the regular size 510 cartomizers wth reasonable success.