As I don't know Korean(I bought the system from Korea, they only bundle Win Korean Version), I installed Windows 8 Pro.
1. All the drivers and Apps were working fine except, Alienware OSD. However, this didn't effect the function buttons but the "Switch Display(F1)" buttons, which pops the change resolution dialog whenver I hit Fn+F1. Windows+P combo was however popping the screen change option slider.
2. The performance seemed quite good but for the past few days the system sometimes slows down terribly. In the resource monitor the memory shows almost 100% used even if I close down all apps. If I restart the system sometimes the system starts perform normally but at times it remains the same.
I am not sure whether I should install Windows 7 Ultimate or stick with Windows 8.
Also, I'm wondering whether I have installed Windows 8 properly or not. Can anyone point me to some datapoints for Windows 8/7 clean installation with msata caching?