The NUB is a marketing gimmick imho.
Yes, tar builds up in the leaves as you smoke a cigar. With some you can see this build up in the end of the cigar, and yes, I believe that this contributes to the "development" in flavor during smoking. I have seen photos and read of instances of the tar-build up at the head of some cigars being extreme, but I have never experienced any that I couldn't deal with.
Bookmarks