Hello all..... As the title states which drive should i go with as my main drive. I'm guessing the WD drive will be faster although it has less cache, am i right in saying this? thanx.

(I SHOULD RECEIVE BOTH DRIVES IN THE COMING DAYS). I will create a system image of my Windows 7 onto the drive that should perform the best, and i recon the 640GB WD drive will?

I currently use as my Windows 7 64bit main drive: Western Digital Caviar Blue WD5000AAJS 500GB 7200 RPM 8MB Cache SATA 3.0Gb/s aswell as a ST3300620A ATA Device (300 GB, 7200 RPM, Ultra-ATA/100) IDE drive.