Originally posted by biz-engineer For me size/weight would be the most important thing.
Let's make the following irregular comparison ...
Pentax KP (APS-C): 131.5 mm x 101.0 mm x 76 mm, 703g
Canon EOS R (FF): 135.8 x 98.3 x 84.4 mm, 660g
In January 2018 I wrote this thread ...
KP-like mirrorless solution
I thought of an APS-C solution because I was looking for a more lightweight travel camera than K-1 is and the K-5 doesn't support the electro-magnetic DA55-300PLM aperture control mechanism.
Subsequently I checked different Cameras with EVF (Olympus, Sony, Canon) in a shop. I really didn't like these EVFs. The image while panning was a pain for me. Further research showed that the KP with the lenses I'd like to take with me wouldn't be much worse in weight and size as other solutions (MFT, APS-C), so I bought the Pentax KP in May 2018.
Concerning size the KP is what I really like to use while travelling. I wouldn't like to go much smaller because ergonomy would suffer.
So if I'd get accustomed with EVFs, a similar camera like the Canon from Pentax as a FF camera based on a KP-similar design (with FF and APS-C mode) would be a great move. Would this be sufficient. I guess no. They then should IMO put PLM motors into the APS-C and FF Limiteds to get a modern lightweight APS-C and FF line. And they should put an adaptor into the package similar Canon's “Drop – in filter mount adapter EF – EOS R”" and other specs like USB charging etc. - both great steps IMO.