eVGA 7950 GT KO SC vs. 7950 GT KO

I know the difference between the 7950 GT KO Superclocked an GT KO are
basically 40MHz in the GPU speed. But does this make a whole lot of
difference. But there is only a $25 difference between the two if you check
online stores for best prices. But why spend an extra $25 if there is
negligible difference. I don't care to mod, overclock, or revise BIOS if not
necessary, just want a solid performing 512MB video card.

I am replacing my 7900 GT KO SC with a 7950 only because I am building
another PC for someone else, and they said it would be fine if I used my
7900 GT that is being used in my current machine. I figured if I have to buy
a video card anyways, he can get a discount, and I can get something a
little better. Plus it seems games these days are beginning to like 512MB.