I'm going to upgrade the RAM in my Powerbook 1.67 from 1GB to 2GB. I currently have a single DDR2 pc4200 1GB stick in it. Now is it worth buying two 1GB sticks of pc5300 RAM which according to Crucial is compatible or should I save money and buy a single 1GB pc4200. Is there a noticeable difference? Is my Powerbook capable of utilizing the extra speed?