Here is an example of a long post that requires a good deal of reader perseverance to arrive at its main point. To wit, CDC obesity studies since the mid-20th century underwent a change in demographic sampling partway through (with more blacks and Hispanics sampled), resulting in a likely overstatement of obesity trend statistics.

The post title gives a hint, but the article would have been improved by indicating where it was headed much earlier on.

In contrast, this post delivers its message regarding the interpretation of "accurate more than 90% of the time" (including definitions of sensitivity and specificity) in a straightforward manner. I wouldn't describe the post as terse, but I give it high marks for content/length.