I have Leopard 10.5.5 running on my S10. I replaced the memory with 2gb and the harddrive to a 500gb scorpio blue. So far it is running amazing. I have a windows 7/leopard dual boot and have no issues. Very quick startup and excellent stability on both (although win7 isnt as good with multitasking as Leopard). Everything worked out of the box with Win7. Leopard I had to work with for a bit, but now the only thing I dont have is the mic. For some reason when i tried to install the fan drivers the first time it killed the install but that was the only real setback. I have now created a .iso dvd and a full restore disk on a usb drive with all the drivers/updates to get the full install working (minus the mic). I think thats the best thing to do while we wait out the next few months to make sure the patched .iso's are stable.