The French disc doesn’t look that great to me either… sure the aspect ratio may be the correct one but it is still cropped quite a lot from the bottom (and if it really was filmed in 1.85:1 and the current disc is 1.85:1 then it has to be cropped from one or both sides as well). But I guess maybe still better than the rest.
Although it does look too heavily filtered to me. There is this one website with comparison shots with the Japanese release and couple of images had most of the snowflakes missing from the French disc (surprisingly couple were missing from the Japanese as well…). And one image had really bad compression artifacts but that might be just one very short instance during the whole disc (I would still spot it though when playing ).
EDIT: Here’s the website: http://dvdfreak.bloudil.cz/freak.php?p=grandesilenzio&dz=0
the comparison images are at the bottom, just place your cursor over the version you want to see and it shows it (it might take a while at first because it has to load the image). The last image has the snowflakes, one other image has some of the splinters(?) missing.
And it looks like the French disc is also cropped from the top… or it seems to vary a bit if the cropping is at the bottom, top or both.