This is what I read...I don't buy it though...it says up to 90% of THC gets consumed thru the vap...around 48% from water filtered bong...and only up to 28% from a joint...I think it's a bullshit study, I still love my joints and will probable never own a vap....IMO
...but, my dispensary has a vap room...I plan to try it soon, but it still won't sell me on their numbers.