I agree with your insights regarding the sidekick's range. I don't find myself throwing it alot. Again, I find it to be a high-payoff high-risk technique, and I believe those are to be used sparringly. The context, in which I find it to be most successful, is chasing after being set up with a combination.
Something about the chamber, though; someone who is flexible and practices this can deliver that kick either high or low, choosing the level at the last instant. Personally, I believe that all kicks should be chambered high (if you're going to chamber) for the sake of getting more power -- and decieving opponents. But, as Onganju did mention, there are many ways to jam a sidekick. Luckily, if they're backing up, its very difficult to change directions quick enough. =D
Also, the prospect of the next generations of MMA utilizing such techniques is exciting, but... what's the mongolian chop?! x_x;