World buildingI've never been interested in world building in RPGs. I'm not that interested in creating a framework or society, I'm interested in creating stories within someone else's framework. This is probably why D&D has never appealed to me. While it has a ready made world, its very much "generic fantasy land", with fluff tacked on from here and there. I could move the system elsewhere, but 3E is inherently unbalanced, with ridiculous magic, that would only create certain types of societies. I can't tell stories that I want in D&D.
The reason I like WFRP and L5R so much is that I enjoy the worlds they inhabit, and am happy to play in their worlds. The systems are designed for these worlds, and work well in them, and are not easily exportable, other than to worlds that function by the same kind of rules: escaping low fantasy would be difficult using WFRP, and the structured societies produced in L5R are somewhat inevitable in a world where death comes very, very quickly.
This is my main problem with Dark Heresy. While it lives in a universe I enjoy greatly, the system, exported from WFRP with extra bits tacked on, grates against the world. Dark Heresy is a universe full of hideous gribbly threats, and you are employed by the inquisition. So you should be able to destroy some random gang punk without too much difficulty. You certainly shouldn't fail your goddamn perception tests every 5 seconds. I might be able to make some fixes to it, but I do wonder if a whole new system needs to be connected to DH to make it more fun.