after installing Jag a month back I have to say I was less than pleased with the speed on my iMac 500 with 512 Mb RAM. I have changed this lumbering sloth into a zippy lil number by switching off window shadows usinf a free utility called Shadowkiller and using Themer (also free) to add my own desktop theme which doesn't use quartz extreme. A mate was so impressed by the performance increase he has put off replacing his old G3 for a while longer. It is so good to have the 'snap' back in the OS and the difference in the desktop is hardly noticeable. Just a pointer for all those who dont have a boss/trustfund/oil well in the garden and can only drool at the thought of a 'professional' system.