BilbertI ordered one and it arrived just now. I'll let you know how it is once I try it out.
I've played some TF2 and I've done a bit of typing on it. The RK-9000-V2 is the first mechanical keyboard I've ever owned. It feels pretty good. The Cherry MX Black switches are somewhat stiffer than the keys on the Apple Keyboard A1048 that I was using before. One thing I didn't expect is that the keys make a small twang sound when released. Is this normal for Cherry switches? The keyboard itself seems pretty robust. It doesn't creak when I move it on my desk, and the keys don't rattle when I rest my fingers on them. One thing I don't quite like about the Cherry MX Black switches is how heavy the shift key is. It's a little bit heavy for my pinkie finger for some reason. Other than that, the num-, caps-, and scroll- lock lights are extremely bright if you look directly into them. They're fine from a normal typing position.
So, I'd say it's worth $30 as a keyboard, as long as I remember to do the rebate.
That's all for now. Maybe I'll add more if I notice something in particular.