As far as the Itaste VV, if I am not mistaken it is basically a high end non replacable and when the battery dies yo have to toss a $60 piece of equipment... Also when on the charger, you cant have it out in the yard.
A mod that takes 18350 or 18650 batteries will last until you break it andyou can get extra batteries and take them with you. (a case with 2 18350s fits my front pocket fine) I can get spare efest 18350s for $5US and AWs for $8
I admit the charger will run about $15 to $25 depending on what you get, but you are only charging the battery, and good ones can go from 14340 to 26650 and will last for years.
Not putting down Innokin, just giving some options
Ah, looked it up, yo can get the Innokin for around $35 and they are 800mah and will pass through but I do not see that the actual battery is replacable....