You absolutely need cavitation in VG mixes, especially.
VG is so thick that the blending of flavors really requires an Ultrasonic steep to blend the liquid properly.
You can either buy one (Ultrasonic jewelry cleaner) for under 30 bucks or you can improvise like I did with my redneck steeping
device ( which is a big fan from an attic affixed to a square wooden box/frame. The bottles of liquid are jammed in between the fan cylinder and the wood. The thing vibrates like a jackhammer and in three hours the
juice is steeped so well that the nic even changes color!)
As far as VG flavors, yeah there's a difference. All VG means lack of the "throat hit" that emulates the "feel" of a real cigarette.
The way you get around this is to increase the nicotine slightly and/or up you watts on your device.