Got the Joyetech VTC mini from cignot today - thanks Vicki....
Comparisons....
left to right
istick 30, Kanger Kbox mini/subox, Joyetech VTC mini
Eleaf GS Air MS(absinthe :- ), GS Air M, GS Air TC
Side view - Kbox mini and VTC mini. The GS Air TC fits flush (on both)
Phil-like nit pick

Below is why I like the rounded Kbox mini (like the Defender) a bit better for 'feel in hand'. And for my hand, the VTC mini fits better than the istick where the istick is small enough I have to bend my finger off the mod to get a good firing on the button. With both the Kbox mini and the VTC mini the 'wrap' of the fingers fully around the mods are perfect for firing. ymmv of course. Because the VTC mini isn't curved, the larger fire button helps. Nice button push as well - no shaky, no looseness, solid. Low frequency soft click.
That said - the VTC mini has the spring loaded center pin, TC for Ni and Ti, I like the display - they feel about the same weight - nearly the same size/dimensions.
The VTC mini ran the Ni coils just fine - just like it's big brother VT. Very simple with replaceable coils. Usually vape around 13W for the flavor - espresso - but cranked it up to 30W - nice but still prefer the lower wattage. Just had it a day but so far nothing that I don't like about it and everything functioning as it's supposed to.
Here's (below) the two minis with the iJoy Asolo on the left. The iJoy has the kanthal temp control/phil says taste control - but it actually does the same math at 4 decimal points vs. 2 and as Phil says it does what it's supposed to do. And while he had 'mixed results' on some aspects - mainly the off wattages at 100 and 200W - vaping at never above 15W (except for 'trying out features on a new purchase' , the Wattages are in an acceptable range and vape much like any other mod I have at the same wattage. Hopefully they'll have a mini version in the future... :- )
DSCN1211 k.jpg photo - kentc photos at pbase.com