Ed, looks interesting. However I couldn't find any independent reviews on it, just "Be the first to review this item". Beware, nothing seems to work as good as the promo vids! I have tried all kinds of short cut tools that turn out to be pretty worthless in the real world.
These discs were bought at True Value under rust/paint buster something, ate up 2 of them removing surface rust on a 2x2 sq ft area.($10.99 ea) Snap-On man talked me into trying a rubber fingered abrasive impregnated right angle die grinder wheel. Very little progress with that also. But, you never know when you will stumble onto a winner!