I would strongly recommend taking the summer crimlaw course. I think around 75% of incoming 1Ls take the five week summer course, which in my opinion gives those who take the summer class a heads up over the other 25% when classes start in the fall.
While it would be nice not have to worry about law school during your 0L summer, I think the class is a nice intro to law school. During the summer, you'll meet the majority of your classmates, find your way around the campus/law building, get a feel for how law school classes are taught, etc... Additionally, I think the summer crimlaw class is taught at somewhat of a lower level compared to your fall classes because your prof knows that this is your first exposure to law school. Accordingly, in addition to the substantive course material, much of the summer is based around learning how to outline, exam writing skills, statutory interpretation, etc...