Do these things really work? Will it make that much of a dif? I am a PC user and have seen the ad on chips that they used to make for older PCs.... They really didn't do that much for ya. The biggest prob with them was the system was still old so the bottle necks didn't get the upgrade. Is this the same thing with upgrading an older G3. I am looking at the 450 to 600 mhz kits. But I don't want to toss money out the window....(excuse the pun) Any ideas or help?