Canon 5D markIII with MagicLantern could produce superb RAW footages. I never graded better source material.

Unfortunately, production is huge luck. You cannot preview recorded footages (only BW, low res, low framerate preview). Postproduction require extra step of converting fotages to something more common like ProRes 422. Which is another place for error.

TLDR it is not suitable for professional production because of lack of preview on set.