Personally, I see nothing wrong with the Subtank Mini. It's kind of the benchmark for mass-produced sub-ohm tanks.
I found mine was awful and went back to my eGo ONE Mega...
Juice ran too low for adequate wicking, even with over 1ml still left in the tank.
Was a bit fussy on some settings, could be a bit leaky/condensationy, taste was a bit off with the plastic drip-tip, generally a lot of hassle and disappointment.
Build quality felt good, but that was about it, for me.
I just got an Aspire Triton and so far am getting on pretty well. HUUUUUUUUUUUGE clouds on the 0.4Ω coil, to the point where even the smokers outside are raising an eyebrow!
Top filling mechanism is great, though can be a bit messy with liquids that use a fat pippette. Reasonably easy to use most of the fluid before it drops to an unwickable level.
Aside from utterly burning through fluid (used 6ml over 3 'fag breaks' just this morning), my only real complaint is getting a lot of fluid collecting in the chimney spaces. Not sure if that's condensation or what, as I'm only just coming up to the recommended 25-30w range at this point. I still have the top vent fully closed and only vaping a 60%VG Cuttwood sauce, but there's a bit of spitting and I imagine that is what's causing it.
Anyone have any insight on what's happening there and how I might cure it?