Hi Squilky,

My suggestion to you is to go ahead and try the Gatorade Prime at least once, and see how it compares to running without it.  For me, I always take a caffeinated gel (GU octane) prior to any race, because the caffeine and sugar boost help me to get pumped up for the race.  On long training runs, however, I've stopped taking energy shots for any run less than 13 miles.  Greg McMillan of McMillan Running has an interesting article regarding long runs and fueling during these runs. http://www.mcmillanrunning.com/index.php/articlePages/article/2

Physiologically, as long as you're eating properly your muscles will definitely contain the glycogen energy required to get through 5-6 miles without any supplements.  But in the end, if you feel that taking Gatorade Prime, or a gel, or whatever, helps your performance and keeps you going strong throughout your runs, then you should do it!

Good luck, and let us know what your experience is!