Ive been playing the game for about two days now and here's what i can honestly tell you-
Its an amazing game (for me) Completely sandbox in every meaning of the word. However if you want combat and you came from darkfall i would not recommend this game to you in its current state. Combat is currently not very stable, and might take a while to become so because it is not the primary priority of the game. However if you are looking for a slower paced game with community and world creation and character progression this is what Xsyon is as it stands right now.
Maybe keep an eye on this game untill the combat improves? They seem to be going the mount and blade route of combat which i think is by far the most player skilled multilayer game out there. So if they can get that implemented well its a + in my book.