I have these on my supercharged and coilover'd '94 Miata that is strictly a nice-weather car, thus why I can't rate wet characteristics. I have had Potenza RE750s and the set before buying the ZIIs were Potenza RE-11s. The RE-11s were way above the RE750s, and I wore the RE-11s clear down to the rears being completely smooth and looking like go-cart tires... I don't put many miles on this car and those tires lasted 5 years, and due to lack of a garage at the time, they were subjected to very low temps, so the compound was not the best - I decided to destroy them at a local drift event to give me a reason to buy new tires.
That said, I mainly use my Miata as a driver but also I do a lot of very spirited backroading, tarmac rally stages, if you will. I was going to just throw another set of RE-11s on it, but a few friends that autocross suggested I take a look at the ZIIs. After reading reviews, I chose them. Got them from TireRack within 24 hours of ordering!
Now that they're worn in a bit, I'll say, THESE TIRES ARE GREAT! The grip... all the grip. Taking clover-leaf exit ramps with only scrubbing off a few MPH is fantastic! On the backroads, they do work and instill confidence. Very predictable tire. Ride quality is great, very smooth. There is a bit of a howl from these, not sure if it'll worsen or get better as my Miata has some camber from being lowered... but at the end of the day, it's a sports car, sacrifices have to be made. These do feel a bit squishy at times compared to the RE-11s, and I miss the RE-11s appearance - those are much wider tires and the sidewall with a 205/50 on a 6 wide wheel looked awesome... the ZIIs look like a 'normal' tire in comparison, but this also explains the ride quality improvement over bumps.
I'd definitely buy these again. I'm going to take care of these as far as temperature goes and I expect many years out of them. -MazKid