Well I have ridden quite a few miles in the dirt and an happy with the bikes aptitude for this! Now this dirt riding is limited to gravel roads and some moderate jeep trails so no gruesome single tracks at the moment I'm still trying to figure out tires and gearing for that. I have replaced the front sprocket with a 14T which has helped the slow speed characteristics not to mention improved the launching capabilities on the pavement.
Psimon55 on here has done some dirt with this as well and can chime in anytime.