Im using a G5 Dual 2.5 Ghz Mac since 2004. It's for running my business and I'm curious to know what to expect in the way of a speed bump if I upgrade to a new 21.5 iMac with Snow Leopard. I'm currently running 10.4.11 and everything works just fine. Will I notice a MAJOR increase in speed running standard apps such as Safari and Photoshop? Thanks!