The best resin in Dollfie company.....

Based on what I've actually owned:
Volks - 9.5 I don't know what you could do to make it better, but smarter folks than I could probably manage it? I love the weight, the texture, the colour. Even when it yellows, as my first boy I think has slightly, it's still quite a natural colour. It takes faceup materials willingly.
Crobidoll - 8 I haven't seen any yellowing, I like the colour, and it has some weight to it. It also accepts faceup materials like MSC and pastels quite well.
LUTS - 6 It's on the lightweight side for me, and to judge by the three heads and one body I have from them, colour inconsistency is still a minor problem for them. It takes more MSC to get a faceup done as there's less tooth in the resin.
Iplehouse - 7 On the light side for me, but doesn't feel as brittle as LUTS or Soom. I only have a new rose white boy so yellowing I don't know about. The resin could use more tooth. The pinkiness of the rose white allows him to look pale without looking undead.
Soom tan resin - 5 Felt quite light and brittle to me, needed more MSC to get a faceup done, and was very badly shaped inside the head. The tan skin was a truly lovely colour though.