This is a good discussion, one which I wish I had seen before my oldest son tried either. I know each person's experience will be different so it takes a lot of wisdom to do what is the best thing for each child; but in our situation, because we lived overseas during the time my son was enrolled in DE, I feared that the online CC classes would not be as rigorous as the ones he had been taken with a high school online school. I was absolutely right. I was really disappointed that he had learned hardly anything. In fact, in his English 101 class, he felt that he and another student, who was actually a non-native English speaker, were the best writers in that class. A friend reminded me that often times (not always, I know) your student will be in classes with those who might not have gotten as competitive education as those in universities and private colleges.
Another thing to think about. For some students, the DE classes will look more impressive to some of the universities that are not as "friendly" to homeschoolers. That is, they may require more of your home schooled students to apply than the public or private schooled students, such as requiring an AP or SAT subject test for courses such as language proficiency and science. So this could be a positive for your student in that regard. However, on the flip side, I've heard that students who have earned their AA or who have quite a lot of credits going into the university may have a harder time getting into freshmen or other exploratory classes. If you're student doesn't know what he wants to study but has a lot of DE credits, this may be to his detriment.
I agree with those who have already said that it doesn't have to be one or the other. At least now you are more informed in your decision-making. :)