It depends on the effect the draw has on the smoke and the flavor. In most cases, if I just take the filter
out of a filter pipe, for a very open draw, I get a lot of air with the smoke, and that dilutes the flavor and
also gives little control on the intake of smoke. But a restricted draw just makes it difficult to get much
smoke or keep the pipe going or get much flavor. Some wide open draw pipes do well; they can smoke
a little fast, but they can give an ample flavor and sufficient control. Some fairly narrow airways still give
plenty of smoke and provide an enjoyable experience. So there seem to be various factors at work, including
bowl size and shape, the quality of drilling, the smoothness of the joint between the shank and the stem,
among others. If I had to sum it up as an averaged characteristic, I seem to get the best smoking from
pipes that are medium open, not unimpeded airflow, but ample.