My 2¢
I think that mod attracts the wrong kind of attention. I was in the military, so a grenade mod back then might have caught my eye. But after doing 4 years of high level security work, I'd think twice about carrying around a vapor emitting device that looks like a grenade..
On the performance thing, I'd say this thing is a very weak option nowadays, especially for the money and all the more so for the possibly negative look. It really is only around for aesthetics. A 16350 700mah battery taking device for $40, when there is the
VW iStick for $32 to $36. A device that has 2200mah, and more bells and whistles than the Cool Fire II. Or a
Seven 35, which needs an 26650 battery, and a charger, but you can get into sub-ohming on a regulated device for $25 more. Or a
Vamo, real similar to the Seven 35, but an 18650 battery and only $7 more.
Hope this helps, get the Cool Fire II if you want, but please check out your options!