Ok, as I search through all of these posts every time someone asks if the 100-400 IS lens is any good, 95% of the people jump in and say ?get the 70-200 IS plus 2x extender!? That?s fine and dandy however, if someone will mostly be using it to shoot at the full 400 then according to the shoot out test http://www.luminous- landscape.com/reviews/lenses/400v400.shtml the 100-400 out performs at F5.6 - F11 which is what you would need to shoot at in low light situations so again why would anyone pay an extra $500 if they are not interested in using it for the 70-200 range? What would be the benefit? And don?t say buy a prime, any prime with that reach with IS will cost $$$$$$ were talking under $2,000 budget. I am looking for a lens that I can shoot wildlife and surfing pictures with. And no 200mm is just not a long enough for taking surfing pictures as some breaks are very far out.