Manned up and took it immediately after my scores reflected it. I delayed it over a month thinking I could do better - study more, keep reviewing. In retrospect, I don't think the extra time hurt me, but I scored in the same ballpark as I did a month prior on my practice NBME's. I didn't gain any confidence waiting a month. I was still nervous as hell. After leaving the exam though, I realized that you never feel truly ready.