@ Dave
That's a good suggestion for testing out a pipe, like a controlled experiment.
@ cosmic
Good info about Pease's suggestion of 30+ smokes and caking over the draft hole opening.
I agree with your perspective that any given pipe has a certain way to be smoked well. And in many case, I always first suspect that the 'bad smoker' is actually myself instead of the pipe. There are so many dimensions just in the tobacco: type (species), curing method, processing method, cut, toppings or flavorings, age, etc. Smoking can be faster stronger draw vs slower gentler, deeper longer draw vs shallower shorter, with longer / frequent breaks vs other ways... Not to mention all the dimensions in a pipe, wood, age, curing, shape, draft, etc, etc.
Some pipes may have a larger tolerance while being smoked in different manners and with different tobaccos still provide decent performance; some other just may have a much smaller set of acceptable combinations.
I am not a clencher and I am not talking about the look (e.g. fills, or draft hole location 'flaws') when I use the term 'bad smoker'. I am also not (not yet...) talking about the taste effect on the smoke from the (briar) pipe itself. By not smoking well, I mean burning real hot even when I am puffing quite slow (so slow that I get a real cool smoke with some other pipes, and I mean starting to gurgle quite soon after starting a smoke and keeping on getting back quickly to gurgle after having run pipe cleaners into it, while the same tobaccos prepped in the same manner may behave quite well in some other pipes. I think bothering me are these two major factors which affect the enjoying process a lot.