Me personaly, have never taken it. But some of my buddies took it in Iraq when thats all we had to do in our off time was lift. They said that they loved it. And that it worked pretty good for them.
So Im just going by what they say.
My workout partner takes it and says it does him pretty good. So why not give it a shot.
The only reason I havent taken it is because I just dont want to add another supplement to what I have been taking.