Omso Active Hydration
We were recently sent some of the Osmo hydration product to try. I believe the two essential ingredients in a hydration solution in events over 2+ hours, are carbs, sodium and of course water. Osmo has settled on a carb (glucose and sucrose) concentration of 3.2% which is identical to the Nuun Endurance formula, which from my research is on the low end of optimal if you're going for an all-liquid approach. However, if you also plan on mixing with solid food, gels or bars it could be a good option to go with this more dilute solution.
I tested it on a hilly 60 miler and I've always liked lemon-lime flavor. If you use your imagination it's like drinking a margarita. It went down well with no gastric discomfort, even on the more intense climbs on what was a fairly warm day. I don't always drink carbs even on long training rides but it's imperative to test your nutrition in the few weeks leading up to a race, particularly if you have a history of gut problems.
Omso also comes in blackberry and orange flavors and can be purchased here.