If your Mac is operating at a slow pace, then for that reason alone it is worth the upgrade to OS X 10.6 Snow Leopard.
Cocoa Based Finder: Finder has a new Cocoa Desktop Window and Contextual Menu.Slimmer QuickTime Player: QuickTime X features a simplified GUI with a greater focus on codec support.This version of Apple's OS also has a reduced footprint. This update does not have stacks of new features, rather overall improvements and efficiency upgrades.
Mac OS X 10.6.8 Snow Leopard is an upgrade to the previous version of OS X Leopard.