I've seen posts that come very close to my questions, but not quite close enough for me to understand. So, sorry if this is repetitive. I am currently still using a Canon D60 body, which for the most part suits my needs just fine. I mainly do daylight outdoor photography, usually with a Canon 100-400mm IS L lens. I will soon order a Canon 1.4X tele-converter also. Due to my locations, mainly large salt water bays, the tele-converter won't cure all of my current zoom issues, but it will be a huge help. My main fuss with my "antique" body is that when I do need to crop, as in many bird photos, the image degrades pretty quickly. I know the obvious advantages to moving up to a 40D or 50D in terms of focusing speed and all the other goodies, but should I expect to see an advantage in cropping abilities? I'm willing to pay for the extra megapixels of the 50D if it will truly make a difference in that respect. It seems to me that even with the 1:4 cropping vs. zoom factor that gaining that many megapixels will matter somewhat. Any advice is appreciated.