After upgrading recently to a MBP, I decided to use my old iMac as a bedroom tv and file server. Haven't decided whether to do the surgery and add a 1TB internal or just pickup a firewire external yet. Either way, I'm planning a fresh install to maximize performance and space available since this was my main machine for over 3 years and never saw a fresh install. I have the original restore media, as well a copy of leopard. When I went to leopard, I did it as an upgrade. Anyway, just trying to decide which os to use? Leopard ran just fine, but I wonder which will perform best and which will have the smallest footprint after installation?