The original Fate/Stay Night had an uncensor patch, produced by anonymous. However, the uncensored images were almost all relatively low quality and in at least one case, anatomically impossible. To remedy this, I asked Belldandy100 to create better uncensored images, which he kindly did. In my opinion, his images are more detailed, sharper, and overall better looking and more erotic than those created by anonymous. I released these images packaged into the 'Improved Uncensor Patch' for the original Fate/Stay Night.
However, when the english patch for "Fate/Stay Nigh: Realta Nua" was released, it seems that the project leads decided for some reason to re-add many of anonymous' original uncensors and only use a few of Belldandy100's images. I still consider anonymous' images to be inferior, and now has the added problem of mixing two different art styles in the ero scenes. So for both consistency and quality, I think using this configuration file to restore Belldandy100s images is a better option.
But don't take my word for it, feel free to check the before and after images in the comparisons gallery so you know what you're getting (Warning: adult content and potential spoilers!).