That was my assumption for PSA as well George. I wanted precision, straight edges and crisp angles. But of course I know the need for some "give" in many situations where that exactly flat edge isn't 100% critical.

H&L for the disc sander probably would be a better choice given the PITA it is to pull the platter from my machine (Powermatic 10A 12"/48" combo). Also once a PSA disc is attached, I'll use it until it is totally Fubar'd  since there is no saving it for another time.
Of course PSA is a tad cheaper than H&L so my left shoulder accountant imp whispers in my ear about saving the $.