Originally Posted by makeinu

Fair enough, but allow me to point out that that's not a flaw as much as it's just the nature of the beast.

No machine will ever be perfect. As internal hubs are designed to ideally shift without pedaling they will always naturally be prone to problems at the opposite end of the spectrum (hard pedaling). Derailleurs, on the other hand, are designed to ideally shift while pedaling and, thus, are similarly prone to problems at the opposite of their ideal (easy or no pedaling). So no shifting mechanism primarily intended to be engaged without pedaling can be fairly expected to cope with pedaling which errs towards aggression as well as a derailleur.

So those of us that require the functionality of shifting while stopped simply need to be relatively more careful about the way overzealous pedaling may affect the shifting mechanism. If that's not an acceptible tradeoff for you, if hedging against the potential of self-injury due to hard pedaling is your number one priority, then don't expect to ever shift well while not pedaling because its unlikely that a shifting mechanism designed under the dual objective of shifting with and without pedaling will ever be able to match the best of what's been designed under a single objective.