Dunlop ZIII

The same parent company makes Falken tires.  Some people think they are very similar with the same tire compound. 

I think you're right. I think Sumitomo owns the brand/name but in the USA the tire in produced by Goodyear. I'm probably wrong. It's sometimes hard to keep track of all the changes.

My next tires are probably going to be Bridgestones if they discontinue the Firestones. 

If I get the Potenza RE 71RS I can go down a size width from 205 in the front to 195 and for the rear 215 to 205. 

I believe it will bring back a lot more responsive handling and have a higher level of grip just because these tires are incredibly grippy. 

I fully anticipate my R-S4 getting old before I wear them out. In 4 to 5 years, who knows what good summer tires will be around and in what sizes. You can probably forget about OEM sizes.

Have you test drove the 71RS? How is the sidewall stiffness compare to the Indy 500 ?

That is one of the many reasons I went with 16/17” wheels. There is a little more tire selection. 
I have not tried the 71RS but from what I read they are quite stiff like most Bridgestones. 
They are very expensive but thats because they are the best in its class.

Since the Firestones have become popular I hope they keep making them. They could make these tires for the next 10 years and I would still buy them but like most good things they will be discontinued as they are getting a little old in tire model years.