I was recently
traveling through Narita and saw the iOQS on display at duty free. I
nearly got one for my son to get an opinion on it's appeal, but did not
have any more room in the carry on (Christmas gifts for grandkids). I
think that is a major upside for PM but my ability to prognosticate is
liable to fail in the future.
If you just wanted him to test a few that might work, but right now there is no way to purchase the 'heat sticks' (IQOS cigarettes) in the USA. So if he actually liked it, after whatever supply you were allowed to bring through duty free was exhausted, that would be it.
I'm not a smoker, but for the first time in a while, I did look carefully at the wall at the national chain pharmacy the other day, and I was impressed by just how much "premium" wall space was taken up by various vaporizer/smokeless products.