Why is this? I've always wondered. 1. G4 holds 4 Hard Drives, G5 Holds 2. 2. G4 holds 2 Optical Drives, G5 Holds 1. 3. G4 has the great door on the side for easy upgrade. 4. G4 has a Backside Bus and a Level 3 Cache. G5 Has neither. Only a Frontside bus, and a Level 2 Cache. Why???? Please redeem yourself with the Mac Pro Mr. Jobs!!!