Much wisdom, above. I'm of the "follow the flavor" tribe. And I'm lazy. Personally, unless a codger blend (Carter Hall for me - which I smoke to the bottom only by inattention), I never smoke to the bottom. With Latakia-infused blends I usually lose interest at half bowl anyway. What I often do is stop at two-thirds down, rest and ... dump the last third into a Cob which seems to "sweeten" the bottom-bowl nastiness and makes for a handy short pick-me-up smoke.