There are a couple legitimately useful new features in the NT6 line. From my POV: the new WDDM driver model prevents a large class of crashes caused by faulty g

There are a couple legitimately useful new features in the NT6 line. From my POV: the new WDDM driver model prevents a large class of crashes caused by faulty graphics drivers. ASLR and DEP. Moving all the window drawing and compositing to the GPU to free up some CPU time. Compatibility with newer DirectX software. IE9+, or even if you don't use IE, a modern trident for all apps that embed mshtml. The new task manager in Windows 8 is legitimately useful. GetTickCount64() is guaranteed to exist. The wonderful Consolas font. None of which, by themselves, are a particularly compelling reason to upgrade. But Windows 7 is absolutely a worthy successor if you ever do decide to rebuild your system in the future, and with ~3G of ram the performance implications will be negligible (they're negligible on much weaker hardware than yours).