R3 sensor is BSI and stacked. So it will have low rolling shutter, potential for better DR, oversampled 4K from 6K+ readout and around 6K RAW.The sensor is way different so I cant see that. All it has to do is have the downsampled 4K and no overheating and it will be a great small camera for video. The 4K HQ on the R5 is supposed to be like the best 4K around then add Clog 2, now we are talking. If canon doesnt try to protect clog 2....
We know nothing about the "R5C" but there are 3 scenarios:
- A R5 internals/sensor with proper cooling it sounds more like a R5 Mk2
- A R5 sensor but upgraded with BSI (non-stacked) and better overheating control.
- A FF DGO sensor and in the cinema lineup (C90 or something)