You never said what is the delivery system being used.
When you make your own wick/coils you have more control.
Pre made systems can change during different runs of manufacturing.
Everything effect the flavor of the juice from wick type even the lenght of wick, wire. When you get that perfect juice write every little thing about it in your book. Long or short puffs, chain vapeing, wattage/voltage range.
There is more to it then just the

juice.