I was under the impression that a hard shift is better not just for performance but for the trans itself. The slow sloppy shifting I think would cause more wear and tear on it. My car shifts so hard that it breaks the tires loose and kicks to the right from 1st to 2nd if I'm on it a bit, I love it. As far as the drag strip it shifts so fast I barely notice it.
Correct. When an automatic shifts smoothly it's just slipping the clutch. Slipping the clutch is going to wear it out much faster than it just popping the clutch out.
As far as how it's done, line pressure is increased.