Ive been mixing 50-50 water and gatorade in a water bottle for aggressive rides or races, and when its really hot outside. If its just a casual ride, usually just water.
I got a huge thing of Heed from one of the 24-9 winners who didnt want it, and I tried it last weekend at Palos. It was okay, but it sure did nothing to stop me from cramping up!
Eating a GU pack just before the race starts helps too.
BTW...use a water bottle if you mix any type of sport drink or powder - way easier to clean than a camelback. If you put that stuff in a camel and dont clean it right away, then it will grow mold.