Compete at whatever level you feel most comfortable competing at. If you really don't want to compete open, don't do it.
Of course if you don't compete open but it turns out you should have, you'll cop shit about it, especially from me. That said, usually the person editing the video makes the decisions about where people compete, and as far as I recall, has always done a good job, so what you decide may be irrelevant. You should definitely still agonise for hours over making the right decision though.