The bad side is if you love the battery life on the eGo, you won't like it elips. It's going to be about half of the eGo.
The upside is for such a little device that they work really well. With a PCC and a USB port to keep it charged up on the go, I even tote one around with me. The vapor output and flavor on these things is pretty amazing to me. I used a 6v mod for quite a while and eventually kicked back down to the 3.xV range with an eGo battery and usually some sort of LR cartomizer. The elips satisfies me just as much despite the more frequent battery charging.
The elips and eGo-C are two entirely different products.
Replacement attys are $24.95 (set by Ovale) and
tanks around 6 dollars for a pack of five. The tanks seem to be holding up well (on my device anyways).