the only difference i've noticed the size of the bowl making is in how long it smokes. some tobacs seem to smoke better in certain pipes compared to others, but i haven't seen that tall/skinny/wide/short has much to do w/it. YMMV
I believe the volume (diameter x width) of the bowl is best picked dependent on how much time you've got and how much nicotine you can handle. I mostly smoke flake, so I have a lot of smaller bowls, because the flake usually stronger in flavor & nicotine already. I generally enjoy conical/tapered bowls for anything I want to flavor-intensify, such as virginias, and avoid conicals for burley, as the end can be a bit too bitter for me.
Pack a pot with flakes oriented north-&-south. Then try keeping the edges of it lit. Either you smoke the center column of the bowl (only), or you huff like a maniac, trying to keep the whole thing lit -- frying both your tongue and your pipe in the process.
As far as smoking qualities go, I could never find a difference between a tapered and a non-tapered bowl.
Added later: sorry about my short answers from before. I was posting from work, I really shouldn't be, so I was keeping them as short as possible.
What I meant to say is that, everything being the same, I cannot detect a difference in the quality of the smoke between a tapered and a straight bowl. However, bowl size does sometimes have a significant influence. I find that some tobaccos taste sweeter in medium sized bowls (size 4 or 5) than large ones. To my gustatory perception, this happens mostly with VAs, but it is also true with some of the sweet Latakia blends. However, this is not universal and there are many VA and Latakia blends for which I do not detect any difference. Tall bowls (chimneys) tend to bring some bitterness to the smoke, especially for Latakia-dominant blends.
Wider and larger bowls (size 5 or 6) seem to work better with burleys, but I did not do any experiments to determine if this is true. I may be just imagining it. It just so happens that, unconsciously, I moved most of my larger pipes to the burley rotation. All the pipes with really large bowls (a bit larger than size 6) that I smoked had detrimental efects to the flavor of the blend to some degree, mostly because they dulled the flavor.
I do not have much experience with smaller bowls, so I cannot say anything in that regard. The ones I have smoke just like larger pipes, only it doesn't take as much time to finish a bowl. But I only have 4 or 5 pipes smaller than size 4.
I am biased against tapered bowls because they are harder to ream. I did straighten out a couple of bowls in my pipes and try not to buy any more tapered-bowl ones.
it's interesting to see what works for different people. i see your point yak about flakes in a wide bowl. i've never had much luck w/the fold & stuff, so i partially rub mine out or sorta cube cut 'em b4 loading