I need the detail to keep me focused. Coloring a large area is almost hypnotic for me and I go back into my out of control thoughts and feelings. I really have to stay focused on the lines in the detailed books and it keeps me from drifting.

BTW they also make raised line coloring books too that can be a different experience. All I can find right now are the ones they make for the visually impaired which are expensive. They do make less expensive ones.