I started on a Mistic I bought at a local Walmart (I think all Walmarts carry them now...the clerk said they were flying off the shelves). I've heard it was one of the best "gas station type" ecigs, but I wasn't too impressed. The battery was ok...it lasted quite a while, but the prefilled flavor wasn't my speed (I got the menthol...it wasn't terrible, just kind of bleh). I found myself still smoking analogs if given the choice between the Mistic and a real cigarette.
I quickly switched to a 1100mah kgo. So much better battery life, vapor, and options as far as flavors and accessories. And the price wasn't that much more than what I paid for the mistic kit (the kgo was $43, the Mistic was around $30-$35, I think).