i read a review recently and the x2 6000 compares to the e6600 and e6700
wether its better to have depends on current price
"AMD's two old-school tricks, the price cut and the clock speed bump, have combined to give the Athlon 64 X2 6000+ a pretty good value proposition. Performance-wise, the X2 6000+ is slower overall than the Core 2 Duo E6700, but not by much. That may be a surprising outcome to those accustomed to seeing Core 2 Duo processors convincingly trounce the competition, but these two architectures were never that different in terms of clock-for-clock performance. It stands to reason that a 3GHz Athlon 64 X2 could nearly pull even with a Core 2 Duo at 2.66GHz. The X2 6000+ is also about 70 bucks cheaper than the E6700, making it a pretty sweet deal in the grand scheme of things. Of course, as always, there are better deals to be had at lower price points than this one, but the X2 6000+ offers a compelling alternative to the E6700."
ps: xxx how long are you planning this new cpu to last you ?
if its a good while maybe quad core is the better choice