EVGA GTX560ti FPBx2 or Step Up gtx570

[bigshootr8]

So, I have a bit of a dilemma I'm trying to figure out what would be better for me to do. Two 560's would push me above a 580 but would it really and a gtx 570 is within my price range to step up for the next 60 or so days. just curious what I should do.

 

[Mousemonkey]

SLI'd GTX560Ti's are definitely faster than a single GTX580, I know because I've been able to test it myself.

 

[bigshootr8]

If i were to test using a benchmark service 3dmark 2011 and vantage would it matter if I had the paid version?