I'm currently shooting a 7d with a 100-400l. Success rate of shots isn't that good, I'm not getting many sharp pics as hoped for. I've seen reviews of 7d not getting good results with this lens so I'm considering going to 500 f/4 and selling 100-400. All input is appriciated as I'm no pro. I'm interested mainly in wildlife and also some sports. I often shoot hand held and shoot from my kayak.