I was toying with the idea of trying the new GY asym3, but reading that ........i think I'll give it a miss.
Iv done around 10k miles on my current MPSS including 1 trackday and the fronts are about done, with close to 4mm on the rears .
Should I just replace them like for like or is there an alternative to try @Teutonic_Tamer ?
If you are 100% happy with the Mich Pilot SuperSports - why change to an unknown?
IMVHO, if you have done around 10k miles on a set of ultra high performance tyres, which also includes a trackday - I would personally be happy with that tyre life. I certainly would NOT recommend you use the Pilot Sport 3 - as they are a considerable step backwards from your current SuperSports, and are actually worse than the older Pilot Sport PS2. I can't comment on the new PS4, as I have yet to try them (though hopefully, by next weekend, I will be putting a pair of them through their paces on my GIT). I can still strongly recommend the PS2 - as they are still a superb tyre (and are still being manufactured).
As for other brands to avoid, I would very strongly state the avoidance of any Pirelli, Yokohama, Marshall, Barum, Autogrip, Nankang, Trayall.