I understand your frustration. 690 its just under the magic number (i.e.700). On the other hand, you should step back for minute and realize that a 690 is f%9kin awesome score!!! Don't read into any of the myths that a top five school won't accept anything beneath a 700. What people seem to lose sight of far to often is that there is a lot more to the application process than the GMAT. If your essays are strong, and you have a somewhat unique background and are able to communicate that in your applications process, then IMO you are a very strong candidate for the top 5 with your current score.
From what I have consistently heard, schools only consider your highest score. So retaking should definitely not be detrimental to your application. However, I would seriously consider whether it is worthwhile spending the time re-taking with a 690. You might be better off focusing your efforts on other aspects of the application. Good luck.