FWIW: one thing I've found with some very high-end tires is that they're usable all the way down to the wear bars, and this gives them longer usable tread lives than lower-performance tires that take longer to get to the wear bars. E.g., a set of Michelin Pilot Sport 4S will be practically bald after 30k miles, whereas a more mainstream tire might take 50k to get to that point – but the mainstream tire will start out with mediocre grip and get sketchy by 20k-25k, whereas the 4S will grip hard (even in rain!) until it's bald.
So far, almost every tire I've seen play this trick has been a Michelin (one was a Bridgestone that specifically advertised this feature). I have yet to see a single "bang for the buck" tire that could come close in this department. I'm watching with interest to see if the DWS 06+ can do it, too.