China usually fastest. I don't know Chinese, I can't find the original place of those film.
I know Chinese, and I can tell you that neither China nor Taiwan has any better, watermark-free "original" place. Unlike Hollywood and anime, there isn't a "scene" of release groups or even subber, or scanlation groups for manga. There are a number of legit streaming sites (DMM, R18, Caribbean etc), a lot of gray or black streaming/download sites but no free and watermark-free groups competing for fame and self-satisfaction.
There's the "Yellow ripper" that you mention, and a "Casino ripper" who prefix the film with a minute-or-longer ad (actually nowadays that ad is yet-another live-sex show site, not a casino site, but I still prefer to call that group Casino ripper). And sometimes you come across ISO releases (seem to have dried out last couple weeks) and depends on luck a HD/FHD release that's truly clean.
There are a few well-known repackagers, such as 3xplanet, but I don't think they do anything exact bundle a lot of garbage files into the torrent.
That's about it, my samples are pretty biased by my taste, but I estimate Yellow ripper makes about 55% of releases, Casino ripper about 45% and others (ISO, FHD) 15% (yes total is over 100% due to duplicates). Sadly duplicate isn't higher.
Yes,
@Inertia is right, (and I don't remember ever witnessing the allegedly rustled jimmies) if you are not happy with watermark, go buy a legit copy, which I have done. Better yet, buy it and release a watermark-free copy (which I have not done), that would put pressure on the worst of watermarkers. (actually I doubt it...) It seems the only groups/individuals who have the money and/or access to first day releases (or even first month release) don't include anyone willing to contribute without compensation. (sounds familiar?) Basically you have one kind of leechers complaining about another kind of leechers.
