While I haven't used many of the techniques described in the article, I would imagine in many cases that using the CSS option would produce a smaller web page. This is because all the elements you are modifying (in some way) with JavaScript also are likely to have styles associated with them.

Also, if you're using jQuery (or some other framework) you necessarily add several kB to the file size before you even write any code. While a single style might be on the order of a few hundred bytes. Remember, bandwidth is money and cutting down anywhere you can is important (just ask Google).

This won't hold true for all cases, but seeing these examples has already cause me to think of several ways in which it would. Anyway, creativity loves options! So it’s definitely worth reading.