I'm thinking the tobacco and the ingredients play a part in that, but i'm no expert.
What I get with AF is the harsh sensation, but no harsh flavor, and when I actually doget a good pull or 2 I don't get any buzz at all. This leads me to believe it's the glycerin or something. HH takes 2 coals like a champ, and on bigger bowls 3, and the tickle never appears, the flavor is smooth the whole time. AF is so processed, and HH is so clean.
Maybe it is attributed to nicotine, but that just mans they have a severely unbalanced product from obviously the new cut or using a different type of tobacco.
I can smoke a bowl of tangiers, and if the tickle is there I can at least smoke it like a cigar, but with AF if even a tiny bit touches it irritates the hell out of me.