I still use CG for sports (tennis squash and racquetball) and times I have to be at my sharpest like speaking engagements, important meetings, etc.
For sports it helps with focus, coordination, endurance and quickness. I will ALWAYS play better with it. Before I'd take it if the game was going to be tough and close for the edge. Now I just always take it before I play.
For business meetings, speaking etc it helps me think and speak better, faster and keeps me alert and engaged. And it takes very little to have the effect. Swishing around a teaspoon for 30 second before swallowing is more than enough.