if I won the lottery I'd fly up and hang out in your studio for a day.
also, laraw, check this out. They're very comparable at 400mm and f/8... The bonus is that with the 70-200 + tc, you have a 70-200 f/2.8... with the 100-400, you have a 100-200 f/4.5-5... I don't use 400mm often enough to sacrifice the low light potential and super sharpness of the 70-200. for me, it's a more practical lens. Just food for thought.
also, laraw, check this out. They're very comparable at 400mm and f/8... The bonus is that with the 70-200 + tc, you have a 70-200 f/2.8... with the 100-400, you have a 100-200 f/4.5-5... I don't use 400mm often enough to sacrifice the low light potential and super sharpness of the 70-200. for me, it's a more practical lens. Just food for thought.