Tyre wear depends a lot on tyre compound, road surface, how aggressively you ride, and whether you ride a lot of twisty roads. Riding a lot of highways will result in a lot of wear in the centre of the tyre. Some tyres try to counteract this by having a harder compound in the centre and softer compounds as you move out towards the shoulder of the tyre. It's a bit of a juggling act, as most riders want tyres that grip but also wear. The tyre pressures also come into the equation and are dependant on the bike weight, rider weight, and whether you are carrying luggage or a pillion. All in all it's a big juggling act I've tried various tyres on my K75 Michelin Macadams ( No grip tried 2 sets), Avon Venoms ( 2 sets better grip but started cracking in the sipes), Bridgestone BT 45's ( 2 sets better grip but high wear), and now on Michelin Road Pilots ( even better grip and seem to be wearing better than the BT 45's). With each change of tyre grip or wear have improved I will probably try Shinko's next.
Regards Martin.