Here were my thoughts on what could be better on these....
#1 lets make the bridge (plastic O ring that keeps the poly in place) a part of the cartridge rather than having it balance there. The bridge on the cart will come loose and float into the tank if you even look at it sideways when refilling with a syringe.
#2 having to refill from the polyfill end is a pain, it means pushing the filler to the side and having to readjust it again when finished to keep the seal and prevent dumpage on the atty. Being able to refill from the mouthpiece end would be much better, maybe a plug can be removed to allow dripping rather than carrying a needle.
#3 the plastic used in these carts is way too fragile, all my carts have cracks throughout them from the stress that is required to insert and remove them (i have had these for 2 days). The plastic used in the standard 510 cartridge would work much better and last longer where it stands up to twisting much better than the compound used in the smart carts
#4 They need to make them a bit smaller in diameter, these are a really tight fit and would eliminate problem #3
#5 Im not sure im comfortable with the polyfill being glued in there, glue and e-liquid do not go together, lets keep the carts glue free for obvious reasons.
Allen from cdnvapor.com is gathering suggestions that he will relay to the manufacturer, so maybe things will turn around.
Neon
I sure hope so. What I get upset about is the Chinese surfing the forums and modding their product to one or more of the sometimes proven sometimes not proven mods, instead of doing similar research and trials like vapers do. If we are doing it. I am sure they can as well. Does that make sense. We are a bunch of kicks so to speak, they have engineers on staff, do they not? No offense to the professionals out there...