One in favor of the product, but not the ads
I started using it in October, 2006, before what's his name got involved. I had gotten fired after a car crash caused problems with my memory and mental processing. A supplement called Mental Acuity Formula helped my brain to function. FRS Plus gave me the concentration and focus to excel in three hour evening MBA classes. The Neurologist had suggested I use drinks with caffeine, but they did nothing for me.
The stuff is usually too expensive for me, but when the unemployment benefits started coming again, boxes of lime powder were on sale for five bucks with the purchase of something full price.
I can't say if it helps with endurance, and I've never done the regular energy drinks with taurine and caffeine. I hate seeing the guy on ads, and I hate that he gets even a dime of my purchase price, but I'm committed to the product when I can get it. Except the chews, which have never done a thing for me.