The Mini PT3 does use a dual coil instead of the single coil of the Mini PT2. The dual coils in the 3's does give a bump in vapor and flavor, but making your own coils for them will bump them even more. Making a microcoil to replace the dual coils on the 3 is not too difficult and pretty inexpensive to get into. Cotton wicks will also make a difference. I do find that the O ring on the top of the glass for the PT2 tends to stay with the tank for some reason and can get out of position easily. I would take mine apart now to take pics about what I am talking about, but it is full of Strawbana at the moment and I am loath to part with it for that long.
Ultimately, my experience with both that while there was a bit of tweaking that needed to be done with the Mini PT2 right out of the box, the Mini PT3's I simply washed, assembled, filled and they had a more satisfying experience than I did with the Mini PT2 right away. Don't get me wrong, I like both now. Since the 3's are relatively new, not many have experience with them so SOMEONE has to toot that horn.