Sorry, but even the X2-6000+ can't touch this chip when both are fully OC'd.
Check the reviews at X-Bit LABs for lots of good articles.
They did not compare the chips directly, but the X6000+ was over 10% behind the E6850 in most benches.
Even if an OC to 3.3Ghz (10%) yielded a 10% boost (Unlikely) it still would have lost.
Also OC's to 3.3Ghz are tough since AMD has already boosted the TDP on that chip from 89w to 125w so they could get the 5600+ chip running at 6000+ speeds.
The E2160 clearly beat the E6850 when the E2160 was OC'd to 3.2Ghz.
Perhaps the hand-picked X2-6400s would come close but still would lose on clock.
Maybe, just maybe you could OC to match performance.
You can still get a cheaper AMD System, but even the fastest X2 can't really touch any of the C2Ds.
If they were better, AMD would sell them for more like they used to.
However, they are selling at bargain bin prices because that is they need to do when the chips are compared.
It's just not the folks you consider "FanBoys" making these claims.
It's AMD with their pricing.