Most people say that for small modern non-wood props (< 13") that the balancing is not necessary. An off-balance prop won't cause excessive vibration.

My opinion is that it is probably better to check the balance of the prop anyway, but to "pass" out-of-balance props unless they are way out.

Further, my (limited) experience is that Master Airscrew props in the 10,11, and 12 inch range (which is where I play), are typically inferior in balance, and performance than the equivalent APC props.

I found that switchin from an 11x6 MA prop to an 11x6 APC boosted the "feel" of my plane "drastically". It was a whole new plane.

For a 20% price increase to APC, It is worth the cost.

I am just an impressed APC user... no association to the company.

My understanding is a few-fold. APC props have a "modern" airfoil shape, is more efficient in the air. Less noisy. Further, the MA props have more weight near the tips of the props, where centrifigal forces are larger (centrifigal forces are related to the square of the distance from the hub - so any weight nearer the end of the prop has a significantly more pronounced effect on the prop balance), causing MA props to be more vulnerable to imbalance in the manufacture process.

MA props are more rugged though. A nose-over on a windy day on grass will nick an APC prop enough to be discarded, but an MA prop will just get dirty ....

gus