I use a microfiber wash pad, a grit guard, and microfiber drying towels for cleaning the car. I don't wash in the sun and I dry the car thoroughly. I really don't think I'm adding swirl marks when washing.

There's no way I'm trying a rotary. Given the choice between damaging my paint and living with the microscratches, I'll take the scratches. I hope the new stuff Meguiar's introducing will work with the Porter Cable. I'm definitely ready to try something new.