I think the equation changes a bit if you are dehydrated and trying to quickly rehydrate (e.g. MMA, Wrestling, Judo, etc.) I think in this scenario you'd want electrolytes, less carbs and maybe no proteins/aminos to maximize the osmotic pressure to "force" water into the dehydrated cell as fast a possible. Depending on the sports governing body (time from weigh in to competition) and the amount of weight cut, would dictate when you could then switch from this type of solution to the some of the great ones mentioned in the above post.
Science of hydration is fascinating and open to comments/suggestions/ideas.