Not as far as I can see... For example the first benchmark on the article,
3DM05 No AA/AF 1024x768. 6600GT gets 3681, 6800 256MB gets 2635. Quite the
difference in my opinion....

6800GT or 6800 Ultra naturally are much faster, but the op asked for a
comparison between 6600gt 128mb or a REGULAR 6800 128mb.

4978 3DMark05 if you overclock the NV41

MSI NX6800-TD256MB (riddick) PCI-E

325/600 3DMark05 3758 (default)
420/840 3DMark05 4978

ASUS A88N-SLI Deluxe
3500+ venice @2700MHZ
2X512MB HyperX PC3500

I've had the CPU multiplier default to 5X or 1225 and the 3Dmark05 score is
the same