I have been using my iTaste for a full 2 weeks now. Really the only shortcoming to this device is the included tank (which is decent for a tank) but I figured out a way to improve the vape amount and draw. It's easy as pie.
1. Take a paperclip or even a liquid injection needle and insert it into the hole at the top end of the tip.
2. Gently pull out this insert (it comes out easily, and is not glued)
Note: there is a secondary barrier inside the tip so you will not get any liquid or condensation inside your mouth.
This really makes a big difference IMHO in the overall vape'ing experience with the included tank. I have done this with all 6 of my tanks. It helps by making the draw much easier and natural feeling, and thus getting more vape at a quicker pace. I love my iTaste, even bought a 2nd in chameleon, mostly I use a Smoktech 510 1.5ohm LR Dual Coil Mega carto with the X4 Adapter. The smoktech produces huge amounts of vapor and awesome throat hit!!! with 100% VG juice too. If in the market definitely get at least the 510 (X4) adapter if not the 4pc set because it makes the iTaste really shine as a device. Using this tip for the included tanks makes the vape a near top performing tank system, without this tip it's just above average. I can't say enough good things about the iTaste overall, and for the price it's a tremendous value.
Hope this helps, any Q's about this or the iTaste, feel free to PM me or post here.