I'd take this card over a 6990 and here's why:
It's faster.
It's considerably quieter.
One card failed on overvolting. And so? Defective cards happen, that's what a warranty is for. If it's a design glitch as suggested in the review, they'll recall them and issue ones with improved power circuits. All in all, this incident isn't such a big deal. I'm sure that idiot Charlie Demerjian will jump on it as "proof" that he was right all along though.
<sigh>
I think this is the real killer ace up its sleave: The 6990 is running at nearly full speed at stock. From what I can see, even at full speed with the BIOS switch set to turbo it doesn't win, or just equals. However, the 590 wins the benchies when
considerably underclocked at stock speed. This is unheard of in performance races. How much untapped performance does the 590 actually have then? Significant, I reckon. The 6990 can't overclock much though, can it?
I'll bet you non-reference boards with non-reference coolers come out that make this beast run at full GTX 580 speeds and beyond. The 6990 will then be a distant second in the performance race. Yes, it will use enormous amounts of power. However, that's to be expected for a card that's gonna be used by top-end enthusiasts. These guys are gonna have the rigs to cope with such a card.
Finally, as I've said in a couple of other places now, both these advanced GPU architectures will only fully realize their potential when they're made with 28nm technology. The current 40nm tech has run into the power wall now.