If my tobacco has the right moisture level for that type of tobacco and my packing is right for that cut of tobacco I enjoy the bowl front to back. A english mixture for me a can be a little more moist, where I like a virginia or burley bone dry. A ribbon cut can be packed a bit tighter (3 pinch method), where a ready rubbed or rubbed flake is gravity filled with little resistance when pressing the tobacco in the bowl, a fold and stuffed flake will be pressed only when I tamp it which I generally do very light.
I do think the second third is the best part as the tobacco had time to open up with the ember, maybe some moisture (the tobacco might be bone dry but you get some moisture never the less) has enhanced the tobacco while burning. I don't dump ash the last third, that layer of ash helps for me to restrict the airflow enough to not let it burn to hot so I don't have to adjust my cadance. A extra relight in the bottom third isn't really a problem, I try to touch the tobacco with the heat of the flame, not the flame itself.
If a bowl of tobacco isn't enjoyable from front to back personally I would attribute that to the above mentioned factors.