No it doesn't I have the patched USA version, along with Albert's texture mod and enhanced cut scenes by Sp00kyf0x and there is still quite some noticeable differences in not only graphics, but shaders and how things are rendered as well. also the enhanced cutscenes aren't as crisp as the ingame cutscenes of the Gamecube version.
Yes it does make it look quite a bit better, but still far from Gamecube quality.
It won't be noticeable for someone who has just played the PS2 version, then played the PC version, but you can tell by playing through the Gamecube version and then playing through the PC version as well.
Leon also has a much lower polygon count than the Gamecube version among god knows what else. It was a straight poorly done port from PS2, that not only looked like butt, but ran like it too.