Well that depends entirely on what you are trying to do. Kinda hard to rate the rig when we don't know what the rig is for. Is it a gaming PC? Is it a workstation? Is it a server? How long do you expect it to last you? What are you trying to do with this computer?
As far as your OS goes, I give it a 1/10. W7uses fewer resources, and doesn't send every single keystroke and click you make back to a Microsoft database for them to record everything you do on your computer. Oh the days of XP. I miss those days.