An 8th grader would care what other people thought about them using a CamelBack on a road ride. Just sayin'.

I used one once (in addition to two water bottles) on a long road ride when it was extremely hot and humid. I tour with one all the time. It is relatively small (40 oz. I believe) so any additional heat is not a big factor. It's certainly better than being dehydrated. On tour, one benefit is that you don't have to make as many trips to the campground water spigot when making something like pasta for dinner.