Here's another review of that board:
http://www.hothardware.com/viewarticle.aspx
There's a very very small performance gain, about 5% when compared to the Asus A8N SLI Deluxe. And that's only with 4x FSAA. Anandtech recorded an overall gain of about 4.4%.
The problem with anandtech's review is they reviewed the A8N32 SLI Deluxe against a DFI board with 8x PCI-E slots. Why is that a problem? Different board manufacturers do different crap to their BIOS's and boards. If they had pitted the A8N32 SLI against the A8N-SLI Deluxe, I think we would have gotten an more accurate depiction of performance.
All in all, there's no question that the Asus A8N32 SLI is the fastest board for SLI gaming
But an extra 5% in performance is not worth the extra $100 in my opinion.