Much of your questions relate to what you shoot and where you shoot them. You might be able to walk up to and all around a barn, bridge, tree, or model. You can "work" the subject. But, in places like Yellowstone and Grand Teton National Park, rangers and rules restrict you to being outside 100 yards from bears and wolves. Occasionally, you get to shoot from the window over a bean bag, but parking on the road side is getting tougher. In GTNP, they don't even let you stay in your car within 100 yards of a bear. There are places you can walk around, and others you can't. So, for some types of shooting, large files, with the ability to crop is fairly important. Quick auto focus and fast FPS can also help get shots that people might have missed with earlier cameras.