I recently got the Firehawk SZ50-ep's in 255/50-ZR16, these have a treadware of 340. I have only run them for 4000 miles or so, but I am really impressed. All I have to compare them to are the Z rated Goodyears (245/50-16) the car came with, the Firehawks are truely amazing in the wet or dry, and the ride is also dramatically improved. So far I feel these are well worth their high price. I considered RE730's and Yoko ES100's too. I also put a set on my wifes car with the same results, she loves them.

 

My 730s have about 3K on them and sound like mud tires. They are freaking loud!

I can feel the tires while braking.

I won't buy another set ...

 

I use the RE730s on our 1996 Impala SS (255-50-17 size). They are the best tire for that car available. Appear to be a good handling tire for stock suspensions. Our IMPY pulls the corners pretty well for a boat. They have very deep rain grooves, which tend to get noisier as the tires wear. These tires last us about 30k miles on our land-yacht

I have not tried them on my 1994 Z28 M6 in any size. They RE730 is suppossedly a replacement for the fantastic defunct RE71. Based on the immense surface area of rain grooves, I don't see how they could compare. I would use them as a travel tire, but not an autocross tire.

As for Firestone, haven't they had enough quality issues to make anyone less than confident?

 

Bridgestone Japan bought Firestone some years ago.

i think their perceived problems with the Ford Explorer were more Ford's fault than Firestone/Bridgestone's.

Best tire manufacturers in the world right now:

Bridgestone Michelin