Pretty much every tire will lose wet performance ability as they wear. I remember my stock GS-C's were pretty scary in rain when they were getting old. I would have bought another set, but they weren't made in 205/55R16 by that time. I got about 30k out of them.
That said, I like my RE730s enough to buy them again to replace my worn ones. Best bang for the buck as far as I can tell. I'm getting much worse life on them, but that isn't the tire's fault in this case.
