Got mine in the mail last week and have been using it (them) fairly regularly. To me, the draw feels slighly more airy than the full-size Protank, even though there are only 3 air holes in the eGO base of the mini and 4 on the larger version. The threads of the eGO base are a little meh, certainly not "buttery" on any device I've put it on (Provari using an adapter, MVP, and VV 3.0), but I haven't had any connection issues with any of those devices either. It's kind of long/tall for it's diameter (it's as long/tall as the regular Protank), but this is needed for the recessed eGO threads. No leaking issues as yet (although I've never had any leaking issues with my Protanks and Davides, so YMMV). Overall build quality appears to be the same as the normal Protank. The gunmetal color of the eGO base on an otherwise stainless steel/glass device kind of throws the look of the mini off, in my opinion, but I've heard some people like this, so that's a preference thing.
All in all, it's a Protank ...mini. It accepts the same coil heads and has the same fixed, non-changeable tip.
The only 'bad' thing I have found is that, for whatever reason (and it is likely much more a factor of the adapter than the mini) but the mini doesn't thread all the way down on the Provape 510-to-eGO adapter, so there is considerable gap between the base of the Provari and the bottom of the mini (and no possibility for a ring or a cone). It works and looks fine on devices that have native eGO threading like the MVP and - especially - the VV 3.0, though.
I don't know what I'd give as a 'rating' for this. Overall, my impression is just a ...meh. There aren't any real surprises and, other than the Provari fit, it does what I bought it to do in the exact same way as my Protanks have always done. It's a good device if you need a small glass clearomizer *right now*, or just want it as part of your 'collection', but I'd have a hard time recommending this as a "must have" or "must get" item. All things considered, Kanger is just way too late to the party with this to make anyone get excited about it (especially with the Davide Minis being released soon). If this had been a Protank 2 mini, it would have been a game-changer (and, hopefully, Kanger comes out with Protank 2 minis sooner rather than later) ...but even as it is, it has a very short window of validity in the market.