Osmo Active Hydration
We were recently sent some of the Osmo hydration product to test. 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 for racing. 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 the Lemon Lime flavors during efforts. If you use your imagination it's like drinking a margarita. I also tried the new Blueberry Pomegranate flavor which was some nice variety but I'm usually partial to the citrus flavors. 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.
Osmo hydration also comes in blackberry and orange flavors and can be purchased here.