I agree with Gary. "Deal with" is more genereal. You have to deal with work, deal with this paper due on monday, deal with this person, but "coming to grips" has less of a negative "chore" connotation to it. Example: I am "coming to grips" with this death, with a new idea, with your relality of the situation. In my opinon its more of an epiphany state of dealing with something. You werent aware of the entire scope of what you were dealing with, and now you are starting to.