I, unfortunately, have to rate it a 0. I managed to install it once on my system, and it was running fine (although at the time I still needed the DVD to boot since the default install bungled the MBR boot). However, after mistakingly installing the iPhone SDK and blowing away my abilty to boot/run (because of the CHUD tools), I have never been able to get it installed again. I have now tried virtually all the combinations of options, and cannot get the system to run. I have attempted at least 20 installs with no luck (various kernel panics or hangs).