I just purchased a Canon 500 F4 (very happy!). I own a 6D (20 MP). I understand that glass and technique are both huge determinants of taking great pictures (and maybe a little bit of serendipity). My question: how much will I help myself by getting a newer camera body that has either/both a cropped sensor and/or more megapixels? I do have a 1.4X TC so I'm not sure I really need to get so much closer - I suppose I'm mainly interested in understanding if having a 40 MP (or 30 MP) sensor is going to appreciably enhance the quality of pictures that I take. Thanks for your thoughts - excited to learn!