I think it's an underrated set that could be very potent when used right.The trick is getting a chance to set up a sub, but once it does all the things you listed as counters are suddenly threatened with a super effective attack, which is doubly true since Tyranitar has that perfect Fighting/Dark coverage. So overall I'd think it's a great set to try out that could catch a lot of people by surprise and leave gaping wounds in opposing teams.