My 2 cents... In my experience, the Enduro 3 on the front was a great tire. I got 8,000 miles out of it, on and off road it was a great tire.
The Karoo however; was great off road tire, but it lasted a whole 1,500 miles.. Yes, thats one thousand five hundred miles and it was shot. Cupped like a bad habit.
I now have over 5,000 miles on a TKC80 up front, and it looks as though it will be good for another 3,000.
I am using a D606 on the back, and it is wearing faster than the TKC80's I normally use on the rear. It looks like the D606 will last me up to about 4,000 miles. The D606 has excellent off road traction, and seems to bite the dirt better than the TKC80's, but it's a noisy beast on the road. I will be going back to a TKC80 in the rear. I get about 8,000 miles out of the TKC's on the rear.