I agree that prop balancing is highly over-rated and I don't usually bother to check APC props because they are always very close.

But I once checked a 15" MA prop that was WAY off. Just for kicks (before throwing it away), I "balanced" it by trimming the end of the heavy blade. To get the prop to balance I had to cut off over 1/2"! The only thing that I can figure is that something went badly wrong when it was molded.

Based on this experience I think that it is worth checking non-APC props to make sure that they are at least reasonable.