I got a little over 7000mi on my front Metzler, 3500 on the back, so after two rear, I went the Darkside, Riken Raptor, and put an Avon Cobra on the front at the same time. I've got about 3500 on the pair, back is fine, but I'm watching the front, hoping I get at least 7k on it.
I like it, so I'm ordering another one.