Upload & Sell: Off
I want a 600 II but I don't think I can give up my 800, and I sure can't afford both
As usual, it comes down to what you like to shoot. For me, as a birder, the decision was easy, especially considering FF cameras will always have the edge in terms of IQ. 800mm all the way. The 600mm is great on FF provided you only shoot tame birds, shoot feeder setups or love sitting in a blind! Another way to put it is that if you have a teleconverter attached to your lens most of the time, you've bought the wrong lens.