There are some significant differences between public and private universities. For example, a public school (especially a community college, and especially in California) will cancel a class if too few students enroll. Private colleges create very small classes deliberately and call them seminars. Alternatively, the breadth of study areas is usually much greater at a public university. But overcrowding in classes required for a major at public university means that some students can't enroll in courses they need and end up having to stay for an extra summer, semester or year (again, my knowledge pertains to California universities, but this problem is widespread here).
And then there's the cost. I went to a selective private college, and even knowing how wonderful my experience there was, I know that things have changed since then and that the costs have escalated like crazy. I wonder if they're worth it at this point. It probably depends on what you want to study.
