The trim pro is more about processing in quantity. Doing 5,000 223 cases gets pretty old with the zip trim (I used to have one too). It starts feeling like I am going for some sort of yo-yo marathon record after a while.

I got the trim pro because with the power motor and the universal case holder, I can go pretty darned quick and I don't get too fatigued.
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The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)