While I don't recommend this because it goes against everything that every fitness professional suggests is healthy, I finally found a way to get the lean abs that I have been working for but not getting. Going into my last week of insanity, I still didn't have ab definition... just a very firm tummy that I could feel solid muscle under about a cm of tissue.
So, 2 days ago I started cutting my daily intake down to 800 calories. (which kinda counts as a fast considering the amount of calorie burning I do every day with Insanity) With in 2 days, my abs have tightened up and I can see a line running through them vertically and a little definition up top.
So finally, I have proof... I do in fact have abs. I understand that as soon as I go up to my normal caloric intake I will "soften" up again, but I now know that my desired results are just a few low cal days away.
... weird I know, but for my body, it seems to be the only way to see these results. When I start P90x after I'm done with Insanity, maybe these results will show with less dieting effort.