Quote Originally Posted by HDNitehawk View Post
It sounds like my debate to buy it is the same as I had with the EF 100-400 II. I gave the 100-400 I version to my brother when I bought my first 500mm. My thinking now is to upgrade to the 600mm f/4 and possibly buy the RF 100-500mm as a filler for the other ranges.
That is my current super tele set up. A few years ago I found a really good price on a used EF version II 600 f/4 and then added the RF 100-500 when I bought the R5. I still own all my other EF lenses too and I am very happy with their performance using an adapter.