Location: Aylmer (Gatineau) across the river from Ottawa
It would definitely impact the score, I know it did on my Gen 1.1 Mac Pro. Using a SSD as opposed to an HD bumped it up from about 6500 to about 8800, also the downgrade of the GPU would also affect the Geekbench score.
But still it is an indication of what is possible, a score of >11000 is pretty damn good.
the average on the geekbench mac page for the model is 10844, so that's probably at or about where most will score with stock HDD & card. But the gt120 is an improvement over the stock card. Or maybe i can be convinced to include the 4870 depending on what card ends up being in my new machine.
i've had both the 4870 & the 5770 in this machine. I couldn't tell the difference performance wise. From my brief research it seems the 4870 actually has a more powerful GPU, but the 5770 has more VRAM. The 5770 also has the advantage of using less power.
I ended up keeping the 4870 since the 5770 didn't play nice with my old 30" dell display (a known issue with the card on some 30" displays where there is a occasional snow effect in the blacks, usually remedied by turning the display on/off). I've since upgraded my display to a NEC so i'm not sure if i'd still run into the same issue. If the replacement machine i end up getting has a 5770 i may be able to test that out.
My New Mac Pro has a 5770. Tried it with my NEC 30" and it's fine, but it doesn't play well with my Cintiq when it's connected at the same time. Not a huge deal since i can connect it to a 2nd video card, but i'd be willing to include the 5770 if it interests a potential buyer.