I use two scoops before strenuous track and field workouts. I prefer this to eating beforehand. No complaints, no stomach upsets, cramps, etc. It seems 'clean' because it washes out of the bottle easily.
JANUARY 2014 UPDATE: This is still the best thing I've got for pre-workout nutrition. I should mention that I add two scoops to about a cup of almond or flax milk with one additional cup of cold water.