Upload & Sell: On
Stu, my recommendation to you stands. If you want top notch performance and ease of use, 500 II is a great choice. Also, the 500 MkI is still a great lens, just a bit on the heavy side.
If you want the ultimate supertelephoto lens at the expense of some additional weight and bulk, then 400 f/2.8 IS MkII is it. The lens also makes fine 560mm f/4 and very good 800mm f/5.6 with the MkIII TCs.
Peter, give the 7D's successor near 5D3/1DX AF, add that 400 and goodies and you'd have one fine, quite flexible action kit
Jerry, that is true, although many people are still bothered by the 400 II weight......and call it "heavy". Well, it sure ain't light, but it doesn't herniate my body like its predecessor did.
We need a 400 DO mk II, with improved IQ, and mfd and a further weight reduction of a few hundred grams, then we are talking ultimate lightweight combo with a 7D II.