I am assuming this applies to all hand eye coordination activities, not just speed bagging. I am hoping to applies to darts and I will soon find out. I have reduced my practice routines to just a few minutes a day, focusing on the 60's, the bulls, and if time, 5 randomly determined doubles. So my routine is typically to hit five of the Triple-20, five bulls (inner counts as one for the purposes of this exercise), and whatever my slew of 20-sided dice tell me to hit in the double ring.
I hope the dude is right!