I think I do just as well with my 1hp rig as the 10hp rigs. The difference would be in the longevity of the equipment. 1 hp will polish any cover, 200 covers may wear out the 1hp if it runs all day, everyday like the pro shops do. My grinder is set up with different wheels on each end. If you notice the guy doesn't put a lot of pressure on the part to wheel so he isn't loading up the motor and trying to jerk the part out of his hands.
I was polishing the drain screw from a Harley fork leg last week. Took 2 days of searching for it when it was snatched from my finger tips. Got some much needed shop cleaning done because of it.
