So I take it Dunlops have a harder rubber than others? Maybe not as good on leaning but great on mileage. I need to go look at what kind are on my bike, I don't even remember.
Tires get harder with age, if you put 3 yr old tires on your bike they will be harder than new tires; If you have had the tires for 3-4 yrs and only ridden occasionally they are harder than when they were new. All things being equal, you maintain propper air pressure, etc; And yes, harder tires wear longer but don't grip quite as well. But the difference is slight so unless you ride at the edge of your traction limits I doubt you will notice. But you might feel a little "slip" sometimes going over tar snakes or at oily spots infront of stop signs and lights.