I'm ready to order a system here and am having a hard time choosing between the following combos: (1) Dual 2.66GHz 5GB RAM 1 x 150GB 10K RPM (Raptor) 1 x 500GB 7200 RPM (WD5000YS) 1 x 250GB 7200RPM (stock) 1 x ATI X1900 XT 512MB Bluetooth 2.0+EDR and AirPort Extreme (2) Dual 3.0GHz 3GB RAM 1 x 150GB 10K RPM (Raptor) 1 x 500GB 7200 RPM (WD5000YS) 1 x 160GB 7200 RPM (stock) 1 x NVIDIA GeForce 7300 GT 256MB Bluetooth 2.0+EDR and AirPort Extreme I'd be downgrading the stock 250GB drive and video card for the 3GHz. Is there really a big difference between 2.66GHz and 3.0GHz that would be noticable? Would the extra 2GB RAM make up for it in the dual 2.66GHz? I do a lot of resource intensive work (multiple copies of Parallels running, for example). Which setup would you go with?