I use the Dirt Hawgs for mixed bashing; some dirt, some grass and a lot of asphalt. They hold up well and are a good all-round choice for me.
Some issues you might want to think about
-they are a bit taller
-they are tough as hell, so sliding around on asphalt won't eat them alive
-they won't have as much grip as a dedicated road tire
-you can get a realistic power slide, similar to dirt, on asphalt ifn u wanna
Hope this helps somewhat. If anybody has personal exp with the Road Rage tires, I would love to hear about it too, because I was considering a set. My only concern was that I would just have zero control when I jumped it back onto the grass or dirt. [My space is limited, so I try to use every inch that isn't infested with nasty trees and light-poles, etc.... This means VERY irregular surface quality]