The Halo G6 is the same identical thing as the Volt you see talked about and recommended here all the time.
The only difference is that they use different juices for their pre-filled cartos and the Halo is a little more expensive.
BTW, the Volt has a 25% off sale
through fathers' day, so the price advantage is even greater right now.
I've never used a Mistic, so I can't make a one-on-one comparison. All I know is that both the Volt and the Halo are consistently in the very short list of mini-ecigs that are actually not too bad considering the limitations imposed by any small battery. Other models in that list are the Bloog and Smoov. Like the Halo, the Bloog is the same as the Volt, but more expensive. I'm not positive about the Smoov. Regardless, the Mistic is conspicuously absent from the short list of the best mini-ecigs. But, it's not on the list of worst e-cigs either.