I have an ego-c pass-thru and an ego-v v2. I seem to get a better taste from the joyetech than I do from the vv. Same delivery devices. Same juice. Same voltage. Anyone else noticed this? I'm not sure why.
The eGo-c passthrough has two modes - a 'constant mode' which runs at @ 3.4Volts and a 'variable mode' where it runs like a regular 3.7v batt - 4.2V off the charger, 3.6-3.7V for most of the charge cycle, @3.2V toward the end of the charge.
So it would depend on what mode you have the PT in and how much voltage you have the VV set at. I know that some ejuices taste better at 3.4V than at 3.7V... it wouldn't seem like there would be that much difference but in some flavors, that's the case.
But if in fact, you're at the same voltage and all other things are constant, then it's a 'subjective' experience - with the same voltage, same ohms and same ejuice, there's no other explanation, and the battery is the least variable if the voltage is exactly the same.