So, like many others, I own both.
On a nautilus 1.8 coil (BVC), I've noticed the vamo is "smoother", with less rattlesnaking than the istick. I vape at 10W on the vamo. I've done some conversions and see that I need to run the istick at 6 or so watts because of the mean vs rms debacle.
I read somewhere earlier on this thread that someone had mentioned that the vamo rattlesnaked more than the istick, but I'm experiencing just the opposite. The istick sounds like it's violently struggling to maintain said voltage/wattage, and the vamo just sounds a lot smoother.
My istick also seems more "spitty" (more juice in the mouth than I would like) than the vamo because of this. I realize that they are both PWM regulated devices, so is this all in my head, or are others experiencing this too?
I really love the istick's size and battery life BTW. I even got the bending adaptor, but the hinge is soooo tight. I got it locally, so gonna go in and find one that opens easier.