|The problem with trying to do better than the mounting point recommended by the mfgr is that there are a lot of other nearby interesting mounting locations besides the center of the running surface. One can make valid arguments that: ....
Excellent points, Tom. You've really hit at the fact that any of these points is actually pretty arbitrary. Some are justified by convenience and easy measurability, others by theoretical concepts of what "ought to" work best for one reason or another.
Unless someone has a VERY good reason to change it, I think it makes little sense to mount bindings anywhere besides where the manufacturer recommends. Racers experiement with dozens of pairs of skis, fine-tuning their binding placement by comparing actual performance differences in real life skiing. Few of us have this opportunity!
On the other hand, adjustable bindings do provide "the rest of us" with the opportunity to experiment, and I recommend them. The old Ess/Var binding (now Atomic), high-end demo/rental bindings, and such new systems as Fischer's RailFlex binding (a special Tyrolia binding that mounts on a sliding rail on the ski), all allow adjusting the binding position easily, without redrilling the skis.
Experiement! There is no better way.
I will throw out the usual reminder, though, that it makes sense to work with an instructor while experimenting. Make sure that the reason you "like" one position better is not just because it compensates for a weakness in your technique. In other words, as Tom mentioned, mounting the binding forward (and pressuring the ski forward) makes the ski less directionally stable--the tips grab, and the tails don't bite as well. This might make them feel "easier to turn" and you might like it. But it really just means you're skidding more, and a revamped technique might make you even happier!