I'm completely in agreement as far as this idea having merit! I will be trying to come up with some ideas this winter and if I do I'll post. I have an upholstery machine so I can experiment quite a bit.
I like to brag how strong I am too but after refusing to put the 300 X2 down for several minutes because something exhilerating is about to happen, my arms have nearly collapsed.
Never the less, after a good season of shooting I, like AlanF, like my freedom too much to go to a pod unless there is a very compelling reason. And as much as I'd like more reach I simply won't be going heavier than 300. I wonder if we could fill our lenses with helium.
Actually I'm wondering what a 7D2 might achieve with my preferred light 300 X2 - any comment AlanF?
My own experience, which matches that of others, my 5D3 outperforms my 7D for bird photography for much of, but not all, the time, despite the the crop factor disadvantage. Some of that better performance is due to the far superior AF of the 5D3. If a 7DII with an AF performance equal to that of the 5DIII and a better sensor does appear, I will definitely buy one as it should come into its own when you get close to pixel-limited shots.
5D IV, 5DS R, 7D II, EOS-M, Powershot G3 X, 400mm DO II, 300/2.8 II, 1.4xTC III, 2xTC III, EF 1.8 STM, EF 70-200/4 IS, EF 24-105, 15-85, 100-400 II, Sigma 10-20, Sigma 150-600mm C, EOS-M5 15-45, f/2 22, 11-22, Samyang 8mm f/2.8 fisheye