I gotta admit, an un-interceptable charge does live up to the name of "unstoppable," and I agree that any other bonus isn't needed to make this skill desired.
In fact, I gotta wonder if it would end up being over-powered just by itself. We have so many changes coming with our next rules set I'm going to leave this one out - however, I'm very interested to hear how this change to Unstoppable Charge plays out in other groups.