They look slightly different, but still are both nowhere near as good as no compression.
I think the whole issue with the Q3 S3TC fix, is that it just forces apps that ask for DXT1 to use DXT3 or 5. Like gstanford says, its not a bug at all. Not now anyway, there might've been one in the past, its just happens thats DXT1 looks crap when working correctly.
If ppl want, I can still do some GF4 shots too, but frankly from running the program here, they look identical the gf3 shots. I overlaid the program on top of the GF3 shots, and repeatedly ATL-TAB'd, and they look pixel-identical.
Thats on a GF4TI4600, with the new 44.65 drivers.