Dark Souls has the refinement, but Demons Souls is a lot more guided. There are a lot of moments in Dark Souls when you have NO CLUE what to do next. Demons souls has set worlds almost like 1-1, 1-2, 1-3. Plus the wiki and walkthroughs for Demons Souls are already fully developed. If you can master Demons Souls, going into Dark Souls ain't nothin.