Ok, heres the deal. IanCurtis pretty much summed it up. I'm not bullshittin ya, I grew the damn things in cali for a while, and pretty much grew up on the knowledge. Yes, the trichomes have the most amount of THC in the plant. The hairs have the 2nd most THC in the plant. The way the plant grows, is that the pistils (hairs) soak up the sunlight (or whatever light) and flood the buds with THC. The leaves also soak in the light energy, but as the buds mature there are enough hairs to soak up the energy and bring it directly to the buds instead of supplying the stalks and such with the energy, so a lot of fan leaves are less necessary as harvest time nears. The buds themselves are packed with THC by the time they are harvested, cured and bagged and end up in your pocket and pipe. Yes, the smoke of the first hit will always contain the most THC than the other hits to come, but that is only because you burn the crystals and the hairs. Now another point was brought up, they referred to it as "cornering the bowl", and thats just common courtesy if you aren't the only guy on the rotation of the bowl. Let everyone get a fresh hit of the crystals, hairs and flowers. But here's something else to think about; you said the heat from the flame will most likely burn most of the THC in the bowl (by using the vaporizer philosophy). Now, its true that this can happen, so don't torch the weed! The less flame needed to smoke, the better. But next time you get a really crystalized bud, pack it into a bowl, fire it up, and then flip the bud over. I'll be damned if there aren't crystals still stuck to the bud on the un-burned side of the bud. So no, the first guy to hit the bowl is not ruining it for the rest of the smokers. Any questions?