Been street-legal for over a year now. I ride mine into town, and up and over the mountain pass (20 miles) to get to the trails. Probably put between 600 and 1000 STREET miles on the *stock* tires, and still measured them with 70% tread left. The worst wear I have seen has been on hard-pack rocky trails, not on the street.
I have always subscribed to the "break it in like you're going to ride it" school of thought, so mine was "broken in" the day I took it home. I ride some long stretches at WOT, though (technically) you're never supposed to exceed 45 MPH on a street-legal ATV/UTV in Utah. Anyway... so while never exceeding 45 (cough, cough) I've learned that if you continually feather the gas pedal in and out at WOT, you'll get a little more speed out of it. When you feel it choking out, you back off a little, then get back on it... Takes a little getting used to, but if you just keep it mashed to the ground, it will top out about 3-5 MPH slower.
Anyway... have fun! Just be aware that off-road tires are stickier than DOT tires, and therefore present a bigger rolling hazard on sharp turns on pavement. I recently went to a set of EFX MotoClaws on my 570. Those suckers have mad grip on pavement... probably 2x what the stock tires did. I'm hoping they wear even half as well as the stock Anclas did.