I'm a Linux user, so it was inevitable that DarkTable was going to hit my radar screen. I'm no DarkTable Jedi or anything, but I found some of these videos helpful.
https://www.youtube.com/results?search_query=darktable+tutorials
I just downloaded Darktable to "test it out" and man it's intense ( IMHO). As a C1Pro and LR user, this "seems" to have a lot of more features. But, the interface, and the manual I do find confusing. Going to test it a bit further and see what happens...