Poor design of the top piece, aka the top fill screw. See the attached pic.
It shreds my fingers whenever I unscrew the top to fill it. Do I need a special wrench or something? The heat sink fins are pointless anyway, if I want a cooler hit I'll turn the wattage or temperature down. I feel like the only thing the fins do is cause vapor condensation inside the tip. This was a lot worse on my original Triton (which has a different heat sink fin design), but it's still present in the Triton 2.
Please make a tip section with no heat sink fins; either a solid, smooth cylinder, or one with a shallow texture for grip (something like the Crown Uwell has). A larger circumference for better grip wouldn't hurt, either. As much as I'd like to have seen this in the original design, I would be willing to pay separately for it just because the rest of the tank performs so well. As much as I prefer Aspire coils, until this issue is remedied, I'll probably go back to using my Crown tank.
Also, obligatory gripe over the small 3.0mL capacity. Kudos on the many improvements, though!