I've tried Anakee IIIs, Heidenau K60 Scouts and most recently Continental TKC70s on my '06. The Anakees were good, long-lived road tires. I don't think they'd work off-road any better than pure street tires, though. And they were loud... in an annoying way, as the front and back would howl at different frequencies, producing an annoying "beat" sound (good physics lesson, though). On the plus side, they lasted over 12,000 miles (almost exclusively road use), the rear retained a rounded profile till the end, and they magically prevented rain the entire time I had them.
The Heidenaus gave a better grip on gravel and other loose stuff (never got a chance to try them in mud or serious dirt). They were OK on the road, at least to the speeds I was willing to ride into blind corners. Noisier than the Anakees. The back started out squared-off and got squarer.
I only have a bit less than 1000 miles on the TKC70s, but they seem OK on the road and somewhere between the Anakees and Heidenaus on gravel (again, no actual dirt yet). They also seem a little slower-handling on pavement than the Anakees.