I'm still on Tiger, 10.4.11. I have consciously avoided Leopard so far for the following reasons: 1)My hardware is older - G4 (PPC) 1.33Ghz and 1.5Ghz with 1.5GB RAM. So no Intel here. My understanding is that Leopard is SLOWER on older PPC machines than Tiger (a first for OS X, before that, every OS upgrade was faster on older hardware). I don't want to slow down my computers - has Leopard sped up on PPC machines, or is it still the pig that it ever was? 2)Bugs, bugs, bugs. Compared to Tiger 10.4.11, Leopard was full of bugs. Has the 10.5.4 version finally killed most bugs? Is it now as stable as 10.4.11? I still keep reading about networking problems and problems with WiFi. 3)A lot of apps did not make the transition to Leopard, or didn't work as well as under Tiger. How are things standing today? I've thought about waiting to try Leopard when I buy new hardware sometime next year, by which time the "real" Leopard (Snow) will come out. However, in your experience, has Leopard finally surpassed Tiger? Is Leopard ready for prime time?