Canon Guru

Currently use 5DmkIII w/500mm f4L + 1.4x
am happy with results, but the camera "seems" to get heavier every day, am 73
monopod is helpful but not great... I usually shoot handheld for as long as I can 15-35 sec

My question, to be answered with as "little" prejudice as possible, as I do read your responses often, which I find very accurate, funny and of course "somewhat" biased towards Canon ...

How does or will the R5 + RF 100 500 + 1.4 TC at 500 length compare to MY prime 500mm f4L ?
here is an image taken today as a sample ... ONE big issue for me is I believe that ZOOM teles can not compete with Prime lenses... I do know the R5 would have a lot more crop, but will it be AS SHARP as my present combo? And if not, what combo would, the weight my present lens is definitely an issue and I can't afford the 600 f4 III lens.... let me know your thoughts [ related to these questions...thanks! ]

The image is not submitted for it's perfection, just a sampling of how it performs for me.
...regards, Richard