I really like how you mentioned the smell of knotty pine lumber in this article, because that was one thing that I had no idea about when I installed my first knotty pine.
Just to emphasize again, knotty pine has a strong pine smell -- not a light, pine scent, but a strong, possibly overbearing smell.
So just remember that before you start putting up that knotty pine beadboard that you're so excited about. If you can't stand the smell of pine, then knotty pine wood is not for you because it is a strong smell that does not easily fade.
So just be prepared to deal with the smell -- like the article said, many people enjoy it, but if you're borderline about whether to use knotty pine or not, then you should certainly take the smell into consideration.