Very interesting read. I'm not surprised that he's able to do a complete overhaul without falling off the wagon, he's been known to a mentally tough individual all his life. I believe it also helps that he's an intelligent individual who knows enough swing theory to be able to right the ship when things seem to going wrong.
I personally wouldn't overhaul my swing unless something is fundamentally wrong with it, I'll just fine tune the crap out of it. Then again, I'm no Tiger, I'm your local hacker.