I don't use a Camelback on my road bike because I don't like all the weight on my back. I also would rather drink Gatorade than water and I don't want to put Gatorade in my Camelback. (I stink at cleaning things.) I have a saddlebag to carry all the extra stuff (tools, etc.) I need. I have three water bottle holders on my road bike. Two have straight Gatorade - Lemon Lime flavor. And as ausgirl pointed out, on the road you can usually buy more.

I reluctantly started carrying a Camelback when I started mountain biking again, because they aren't usually stores in the middle of a trail and it's worked out fine. They weren't around when I first mountain biked in the late 80s. It's pretty much just a bag and a bladder, little room for extra stuff. That was a deliberate choice on my part to limit how much weight went on my back. I only use it when I'm going to be out more than a couple hours.

Veronica