I have ridden with my smaller Camelbak Lobo (I also have a MULE which I use mostly for MTB rides as my MTB can't fit a larger bottle and only has one mount) on road rides but I've found that there's little advantage for me. I still carry water bottles because I like to have something I can squirt from from in order to wash myself off... especially if I've crashed. On longer rides, I'll carry one bottle with water and another with a sports drink. I wouldn't want to put anything but water in my Camelbak. I find that there are plenty of places for me to refill my water bottles so the Camelbak just makes my back hot without adding much real functionality. For most short (under 50 mi) road rides, I am quite happy with a single water bottle filled with water and nothing else. If I am planning on being out on an all day ride in sparsely populated areas then I'll consider taking my Camelbak along with both 20 oz. bottles. The Camelbak will also allow me to carry extra gear, jackets, etc...