I've owned a couple of T-Priv 3's since they were released, a nice solid mod and very sci-fi looking which appeals to my tastes.
Pro's:
Despite it's size it's very ergonomic and sits nicely in your hand.
Fire button bar is one of my favourites, very responsive.
Simple user interface screen, though it's small it's still easy to read.
3 batteries gives a long life between charging.
Ideal for high wattage tanks or coil builds, anything over 120 watts this is my goto mod.
Secure battery door and easy to see + and - symbols.
Cons:
Fingerprint magnet.
Not very pocket friendly.
Quite heavy.
A mod you have to treat carefully to avoid scratching, I'm a little OCD looking after my mods yet I still have a few light scuffs on the base.
Batteries last ages with most tanks, I was getting around 2-3 days when I used it exclusively with a Prince tank vaping around 70 watts.
As mentioned above it's not a juice guzzler, the tank you put on it determines that factor, I have a TF V12 Cloud Beast King on mine at the moment and even that vaping at 130 watts doesn't consume as much juice compared to my Falcon Artisan with Mesh coil at 75-80 watts which is a juice guzzler but better flavour.
Current prices of this mod are a bargain if you shop around.
Final note, I do love this mod but I have to admit it gets little use these days, not one I go to grab when going out.
Size comparison to a few other Smok's I own, it's not as big as I expected which was a good thing, obviously it's girth is wider for 3 batterries: