Just saw this.
The TKC 80's are much more aggressive than the TKC 70's. I have a set of TKC 70's on my Stelvio presently and they are good tires. I have about 4000 miles on them and maybe another 1000 remaining. The front tire has worn as much as the rear but that's due to the braking forces.
The wear of the front is enough to make it growl a bit on pavement.
I do both on-road and off-road.
I am very soon going back to perhaps my favorite tire- the Shinko 705. They work well on dirt AND pavement, especially wet pavement. I do not want a high-mileage tire because that means hard rubber and that means less traction on the curvy sections that are fun to ride.
The side benefit of the Shinko is the price. Although this is a secondary concern for me, I can buy a pair of Shinko tires for about what one "premium-brand" tire will cost.