That video shows tip contact time increased by 20% (200 microseconds). Contact time can vary by 5 times that (double the contact time) with the same stroke, just by hitting farther off center. Hitting farther off center also gives more CB action, which of course will look/feel like "hitting it better".Except tip contact time can increase or decrease: http://www.youtube.com/watch?v=zH2PHaGl8Ik&t=3m27s
Bottom line: you can't control tip contact time with your stroke alone.
pj
chgo