I have an iMac PowerPC 1.6 GHz 1GB RAM. Would I experience much of a speed increase if I took an opportunity to acquire a 2nd hand iMac Intel 1.83 GHz Core Duo currently 512MB RAM? I want to know on which Apple Mail would run faster? i.e. a software that comes with Leopard itself. I'm asking this because Apple Mail consists of the vast majority of my daily work used for this machine.