
This lens is such a PITA to carry around with my other lenses (I injured my shoulder so it's really a drag) BUT
It is oh, so wonderful. I love this lens. I took it to the beach yesterday morning (on the Gulf Coast of Florida) and hauled it over lagoons, everywhere with a monopod (which I hardly used).
It always comes through. For the last couple of years I have been using it with my R5. All taken with the 2X Teleconverter.
I can see why you love it. I love the 400/2.8II that my good friend lent me. The images are superb. But the weight is, well, I can only handhold it in shooting position for about 30 seconds at a time. I can't imagine what the version 1 must have been like as it was a lot heavier.