Camera question for developing camera geeks like me... 70-300 DO or 100-400? They're both F4.5-5.6 and both have IS. They're both also about the same price. I'm mainly getting the lens to shoot Schumacher lapping Monaco next May from up in the grandstands I know I'll carry the much smaller 70-300 around much more often than the fairly bulky 100-400. But for this application, is the extra 100mm on the tele side and MAYBE extra sharpness worth the weight? p.s. I'd ask on FM or DPreview but talk of chromatic aberation and pincushion distortion makes my head spin in circles. Gracias! p.p.s. Moxie and Novamac... don't close this thread without at least briefly commenting!