snip ... They also have rebuildable (with replaceable heads) Stardusts now (Ego Vision Clearomizer is it's official name).
Please do not confuse Stardust (or other brands such as eGo CE4) with the Vision Clearomizer's !
The Vision's are the only one (in our experience) that do not leak! There are plenty of knock offs out there that just do not live up to the Vision's quality.
In our last order of a knock off 2 were DOA, but we did not notice until the 24hr DOA warranty period expired, 4 burned up in days of usage (not weeks) & 2 have gotten a couple of weeks wear (as expected) - we wasted $30 on that order.
Have not tried the Vivi Nova so I cannot speak for them.
But as far as Clearomizer's go I suggest you only buy Vision Clearomizer's such as
http://www.discountvapers.com/vision-ego-ce4-clearomizer-v2-clear/.
They can be recognized by:
(1) no thread on the "drip tip" - there is a metal gasket that interacts with the threads in the base to tighten the tip down
(2) the knurled metal in the base (visible at the very bottom of the clear housing) is about half as tall as knock offs
(3) the wicking material looks like small braided twine - see the picture at the link above
I have no association with any vendor. Just know what has worked for my wife & I after some (mildly) expensive trial and error.