Some quick updates...Last weekend I went out for a few hours on the road. I grabbed some single serving packs of Gu Brew since that's what was locally available. Based on my research that was the front runner anyway, so it all worked out. I had also tried a bottle of the blueberry pomegranate flavor earlier in the week so I had an idea of what to expect.
I loaded up 3 bottles (one of each flavor) and set out. I started out with the raspberry and all was cool. I finished it off and started on the lemon lime but that didn't agree with me so well. It might have been that I needed to eat (which I did, and that eventually settled me) or because I was mixing flavors, not sure. Maybe I just don't like this flavor.
I also learned not to set out with 100% mix, because I was really dying for plain water after that. I did find some and off I went. Orange was good too but I didn't drink that until the end of my ride.
Anyway, the Gu Brew worked for me and I grabbed a can at High Gear. I've had a few bottles of it, including 2 today. I was sweating buckets and despite all the beer I drank last night I didn't have the bike hangover after my ride so I guess something is working right.
I still plan to try the secret drink mix I'm just too lazy to order it.