From DPReview. I'd say no good for landscapes, maybe studio and non moving scenes
New to the a7R III is a multi-shot resolution mode that, much like the system in recent Pentax DSLRs, shoots four images and moves the sensor between each shot, so that each pixel position in the final image is captured with a red, a blue and two green pixels. This cancels out the side-effects of the Bayer color filter array, meaning that full color information is captured for every pixel. This has a noise benefit both from capturing multiple shots of the same scene, which helps average out the noise, while also reducing the additional softness and noise that usually comes from the demosaicing process.
However, unlike the system Pentax uses or the earlier, 8-shot process used by Olympus, the a7R III cannot assemble the final images in-camera. Instead four Raw files must be processed using a freely downloadable image processing application for PCs that Sony will offer. The camera must also wait either 0.5, 1, or 2 seconds between shots for the sensor to settle, which is likely to exacerbate the problems of subject movement between the first and last shot.