Popular? Honestly, you can take a look at the Koikatsu (KK) sharing posts below — hardly anyone is updating anymore. There are many reasons for that. First, as long as you have the KK program and search for character or scene shares, basically anyone can call themselves a creator. If you check the Iwara website, you'll notice that aside from the characters being different, most of the works look almost identical because they all use the same scenes. Only a few creators actually put in the effort to modify the motions and scenes to create their own unique style. The rest are just copy-and-paste works with different characters. KK, HS2, and VAM all depend on how the creator uses them — unfortunately, most of what I see are just lazy, copied works.