My opinion is there is no difference that makes one type/style/etc of pipe better for a blend than another, any difference will be minimal presuming no ghosting, making all other factors equal, a better-made pipe will be better for all blends.
I think 99% of the difference is that people unknowingly smoke or load different styles of pipe differently, and this is where the real difference comes in... not from the pipe itself, but how the smoker uses the pipe differently, then incorrectly attributes it to the pipe rather than their own behavior changing.
Even wider vs more narrow chamber, people are probably loading them in the same way, but that makes the loading different depending how you're loading, subtle change to how loose or tightly packed, etc. Same with draft hole differences, or anything else you want to look at. No two pipes will smoke exactly the same way, and if you don't adjust to the pipe and try smoke them all the same way, you won't be, and that'll change the flavor... but again, that's not the pipe, it's the smoker's behavior.
Say for instance you have two pipes, and one draws significantly more open and easy than the other. If you're testing the draw as you load them and you're trying to get them to the same draw, then the tobacco in the more open one will be inherently packed tighter, which is going to affect how the smoke is filtered as it passes through the unburnt tobacco in the chamber, how much of the tobacco is burning at a given time, etc. And if you're not adjusting through tighter packing, then you have to adjust how hard you're pulling on it and if you don't do that, then they're going to burn differently and therefore, taste differently.
