I just bought a tub from the local vitamin shoppe for $31 on a whim because it was on sale. It tastes pretty damn rude. I used 2 scoops the first day and outside of a stimulant effect, I noticed nothing in terms of getting better pumps. Maybe it will pick up after a few days at 3 scoops. I was actually slightly weaker due to the whole empty stomach requirement when taking it, so I'll try and experiment a little with meal-timing and this. Also, I've noticed on several other message boards that some people have complained about negative effects from this on their liver. They didn't say how long they had been using it, but their liver enzymes ranged from problematic to the equivalent of an alcoholics when they saw doctors for check-ups. Their is some discussion too that large amounts of nitric oxide over extended periods of time can cause liver cancer.
The only reason I bought it was because I wanted to see how much pumps are really affected by it. I don't expect anything else with it and won't buy more. Out of all the typically used legal supps out there, the only ones I think are worthwhile are protein and creatine. Glutamine is a scam IMO, supported only by the fact that magazines can't write articles saying so when it takes up 10-20% of their advertisements. Even multivitamins don't seem to do much...they do well in test tubes but just sit there in the body.