I have the EOS 5DMkIII, IV, DsR and the R5 and R6 units. I still shoot with all of them and I would be the last to say that they are not all great cameras. However, the question, as I understand it, is what should one invest in if seeking to make a long-term purchase for landscape that will provide high-quality prints, work with existing optics but be able to take advantage of future developments in optics (since this is a long-term thing).
Without doubt, using a tripod is a habit I would expect experienced landscape photographers to embrace, so I didn't press that one. One can STILL get good images from any of the above units. However, it is clear that the new generation of sensors from the latest generation of MILCs is superior to the old ones and there are other benefits as well. That is why I provided the link to the review so that the OP could make up their own mind based on documented testing and not just our opinions: which I think is the best service we can render.
There are other benefits to going to the R-series. The legacy EF lenses will work perfectly fine with the new bodies, via the Canon EF-RF lens adapters, however it is clear that the new line-up of superior optics is going to be in the RF lens catalogue, so embracing the R-mount is an investment in the future as well as securing the past.
I am not sure about my esteemed colleagues, I am speaking from extensive use and testing of these bodies with different lenses (see my profile for my rather extensive gear list) so I am speaking form personal experience as well as relying on unbiased reviews. For further ones I recommend checking out Dustin Abbott's You Tube reviews of the R bodies and lenses.
cheers, TREVOR
The mark of good photographer is less what they hold in their hand, it's more what they hold in their head;
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris
That is the best solution, IMHO, of course.
