all I can venture to guess is that the people who insist that rusticated and sandblasts smoke marginally cooler might be right. I find if I smoke really slow and super cool like dragging two hours out of an average sized chamber it is dull and the flavor is flatter. Maybe that's what's happening.
Also I find that part of how I smoke a pipe can change due to subtle reasons that have more to do with my perception. For example I want to smoke a churchwarden faster and harder then smaller pipes. I have to remind myself not to do that.