That bike was built for the roads where I live: paved mountain roads, plenty of sharp up-hill and down-hill turns with a goodly mixed of pavement irregularities. I do think the lack of cush drive would tear the zook a new one pretty soon though. I used to have a spare set of wheels with road tires mounted on them for my klr650 and it worked just great, if a little slowly. It, however, had cush drive and took all the abuse I could throw at it.
Since it is getting harder and harder to get a converted dirt bike past DMV staffers, the street legal DRZ ain't a bad way to go. It may not be fast but, when you're riding roads where 60mph will get you killed, speed isn't that important. But acceleration sure is fun to have. Now if we could just drop KX or CR motor in there...Better yet, just go buy a KTM.