I have to say that I was not a fan of that tire and I know it has its many followers. On the Roadster, when I tried one, it seemed to require more input (force) to get it into a turn, but once there, yeah, it held a line great. My theory is that it is relatively flat vs. oval in shape. Looks like yours is getting more wear on the left side, whereas mine wears (regardless of tire choice) more on the right. The bike also drifts to the left when I let go of the grips, so wondering if my needing to slightly pull to the right is causing that. Does yours steer straight when you let go? If not, I might guess that yours goes right.
My tires wear more on the sides given the type of riding I do. You ride similar, so I'm surprised that you don't see this wear pattern on all of your tires. The best way for me to stretch a few extra miles out of a rear is to do an interstate trip to even it out, at least in dry weather. I don't ride that style much, so my rejects tend to have tread in the middle, but bald on the edges when they get replaced.
I've gone to Shinko. Dunlop Elite would be my first choice, but everything is getting too expensive- I know this isn't your concern. Still, the Shinko, which I've avoided because of the lower price until now (must not be good, right?) actually does perform pretty darn well.
I ride hard and I know you ride hard, but we ain't rac'n and I think the difference is not that great between a lot of these tires, as far as performance goes at our level. Still, I avoid Avons and prefer the Exedra Max for sure on the rear.
