Kanger Protank 3 vs. 2 - Just not as good. Halp?

[jgpippin]

The best Kanger performance I've gotten is with this setup:

1. Protank 2 (with air valve base) or Protank 2 mini
2. 1.5 ohm coil
3. Mech mod or eGo

Whenever I try one of the new 3 series - even the 1.5 dual coil on the Protank 3 mini - I can't seem to get nearly as much vapor out of it.

Am I doing something wrong?