If you are self-studying in the hopes of impressing admissions officers, then take the class. After all, if you can self-study what you need to know, why would you need college?
An exception might be if you know you will for sure be attending a college that for sure will give you credit for a good AP score, AND banking as much advance credit as you can (or is allowed) is going to make the difference in your ability to afford your degree. Become familiar with each of your target schools’ policies as they vary by college.