I would have to disagree. Dropping the elbow involves using the shoulder muscles, as well as the bicep. More muscle movement means more things that can go wrong. Since dropping the elbow provides no specific benefit to the outcome of the shot, imo, it is a timing issue. Pros that do it, drop AFTER the strike on the CB. Amateurs do not possess the same perfect timing, and drop at or before the strike. A pendulum swing, with no elbow drop, uses only one set of muscles, and provides the most fluid, repeatable (read: accurate) delivery of the cue possible. Here's perhaps something you may not realize. The cuetip is in contact with the CB for 1/1000th of a second. We can't even comprehend how fast that is (but as a comparison, it takes 4/1000's of a second to blink your eyes...

), and nothing you do can extend the length of time the tip is on the ball (called dwell time). So...in view of that, does it really matter how long or short your followthrough is? Nope. If you followthrough 1/16" through the CB it would be enough. However, it's difficult if not impossible to stop the cue during the swing. A pendulum swing is a very natural, easy to repeat process, that delivers the cue in a straight line. The CB just happens to get in the way in the middle of the swing...just like golf. The other benefit is that you can teach yourself minute differences in speed control much more easily, than by dropping the elbow. not jmo...
Scott Lee
www.poolknowledge.com