So I finally got the 5-disc version of Box #1... and here's a comparison shot:
German 3-disc VS German 5-disc:
As you can see there is more artifacting (like JPEG "noise") on the 3-disc version. The 5-disc set files are around 780MB whereas the 3-disc are around 440MB average. I'd still have to recommend the 3-disc German version over the North American release.
Season 1, ep 1, German VS NTSC:
If anyone wants the German Box sets (all of season 1-3 + European Vacation), send me a PM.