Saw him about 10 years ago, along with other speakers at a Peter Lowe seminar. THought he was winding down his career then as he seemed pretty old but I guess he's still at it. He's very good and entertaining....you'll think you can conquer the world after listening to him for an hour or so. The only problem is that listening to those speakers rarely turn into life-changing events, and my go for the gusto mentality after hearing Zig waned a few days later.
As far as motivation speakers go, I tend to think you pretty much have to
play the cards that are dealt you...you either are a motivated person or you're not, or perhaps somewhere in between. But that said, you'll enjoy listening to Zig, and if he can make a difference then more power to you.