Played a bunch of ARK both official and singleplayer. Have only played CE as singleplayer since I have no desire to plan my life around maintenance of my stuff on a 24/7 online server (a harsh ARK lesson). That said CE has a bunch of things to do and the devs' efforts are worth every penny. Some areas still need more than just minor tweaks (NPC's artificial intelligence for example). The building system is much more user friendly than ARK's. Decent amount of mods available to improve the quality of life and spiff up the game.
I'd buy it again if I had to.