Hi Bobalex,
I use PG/VG/nic 70/30/11 in my juices.
My nic is PG based (Totally Wicked Platinum Ice 54mg).
I use a calculator to mix everything. So for my Cowboy Blend mix (made 5ml today) i use 2.38ml PG, 1.5ml VG, 1.02ml nic (from 54mg base that makes 11mg), with 0.1ml flavoring.
2% for Cowboy Blend. But for my other flavors it varies a lot of course. Most FA tobaccos go around 2-4%, with the exception of RY4 (10%).
Only (minor) issue i had with the experiment was that one of my bottles (PET) melted a bit so that the bottom became round. It doesn't sit straight on the table anymore. I used warm water and the heater was on. But in my 'old'-style steeping process i never experienced melted bottles, and there i used boiling water.
Could it be that the water also heats up by simply using the ultrasonic (molecules hitting each other, thereby warming up)? Next time i will use hand warm water to see if that makes any difference.
Anyway, the GUCE results are beyond expectations.