Same ideas. You have sugar in your mouth all day and less saliva to boot.
Apparently RunningMommy got caries on the sides of her teeth from the sports drinks, right?

I think gels and water is preferable. Or a bottle of high conc goop and a bottle of water on the side. Take a sip of water everytime you've ingested sugar. There are even 2-chamber aero bottles that would do that.

Plus I don't drink enough when it's sports drink because I get a icky sticky mouth.