Yeah I had one and it was pretty crap, lasted about 3 weeks before it just suddenly stopped working. I got an Ego Booster because I had like 7 Ego batteries lying around. It's nice to have a VV mod that is portable to probably the most pervasive battery around, and you can dial it in exactly where you want for a specific juice.... unlike the 3-setting weak/OK/burning settings of the ego vv passhtrus.
The downside is, paired with the 1100mah battery, and the ego booster attachment, the thing is ridiculously long.