Bunks

This has been done before and mods might move your post to the tyre section. However I'll give you a first impression on Bridgestone BT21's. I do exactly the same type of riding as you. Mostly along A roads without too many shap bends.
The BT21's haven't squared off and the grip in rain and dry seems good to me. The rear tyre is wearing really well, I didn't record the mileage when I changed them but it must have done 4000-5000 now and looks like new. The front is different though. I would estimate it's done about 6000 now and it is well worn. Don't know why the front is wearing quicker I always thought they wore slower, it also seems to be wearing unevenly on the tread pattern. Quight difficult to explain but where the grove in the tyre runs across the treat pattern one edge is really warn and he other edge isn't and has a large step up. I thing when I need some more I'll try Avons they get really good write ups on this site.

Hope that helps Nick