Simple answer to initial poster, without looking at other posts in the thread...
When you're consistently finishing top 3 in fields of 12-15+ golfers on days when you feel, in your mind, that you're playing poor golf... it is time to move up. I apply that logic to the idea of moving up from any division. Don't base it on wins, someone can always get superhot and beat you without being better than you. But rarely are more than 2 or 3 guys going to do that if you're really better than the field. So when you can consistently place at the top when you feel you're playing poor in a deepish field - it is time to move on and step up.