I have a new 09' 20" iMac Core Duo 2.66 with Snow Leopard. Shut Down: = 7 Seconds. Tried 4 times, same result. Start Up: 42-44 seconds to Login Screen Login To Desktop fully loaded: = 6 Seconds I am not impressed by the Start up or Login. I believe I clocked Leopard at the exact same speeds. Overall I am not noticing much difference in anything.