Chris Horner is known for standing while pedaling in a higher gear during a long climb, where most other riders will sit and climb, only standing on occasion. I'm guessing that was his point.

As you mention, it is good for a quick acceleration, so it does take some practice to do it mid-paceline while maintaining the same speed. Probably better to do it at the end of the paceline if with a group. It is good to give the butt a quick breather.