A bit of old and a bit of new, I would probably give a 5. As a gaming machine its lacking in CPU power a lot and GPU a bit. As an office machine its overkill ofcourse.
As Reccy points out, as long as it does what you want, don't worry about it. If you have $$$ and want to upgrade it, where are you having issues? What does the computer do or not do thats p!$$ing you off?