The other reason the traditional scrollbar is useless for gauging progress is one never knows how many pages of comments are at the bottom of the article you're reading. The article could be one page long but have 30 pages of comments and you just don't know until you get to the end.

In this case, sacbee doesn't seem to have any comments at all (good for them!) but I don't read them often enough to have that fact memorized.