If you are going for an 850W, I would consider this Seasonic X-850 KM3 instead:http://www.newegg.com/Product/Product.aspx?Item=N82E16817151102&Tpk=x850
The Corsair AX850 is based on the Seasonic X-850 KM2 - the previous generation. The new KM3 series has a better design and tighter regulation.
As mentioned, power consumption is going down. You really won't need 850W.
A good 650 or 750W should do you for any CF or SLI.
Currently the Corsair has a 15% discount plus I have $40 in Newegg gift cards.
Is it worth $25 extra upfront to get the Seasonic? I don't realy factor rebates in.
Otherwise, which 750W would you recommend?
$105 out of pocket - $10 rebate = $9S
$130 out of pocket - $20 rebate = $110