My 2 cents (probably about all it's worth...) is the video grab looks like it was taken with a stock picture style and has not much apparent DR as a result. Plus looks like no sharpening in post. To me, these are the more noticable issues than noise.
I've not done much video with 5D3 but did do some testing to gear up for doing some in the future. My findings are that there's a pretty substantial difference to the look when using a picture style optimized for video like FLAAT or similar and then applying a RGB S curve in post as a basis for further grading refinments (if desired), as opposed to using a stock Canon still shot picture style.
For noise reduction, the Red Giant NR plug is pretty good, as is Neat Video NR plug (I own both) and I'd probably say the Red Giant product is the more flexible and easier to use.
Lastly, the softness is pretty easily handled to at least some degree with Adobe's native sharpening tools.
But yes, I'd agree what comes straight out of the camera could stand improvement.
As for all i-frame, I did see a test of moving cars at a distance that were very tiny within the frame and the all i frame looked smoother in the motion of the cars. Again, I've not spent much time on video with my 5D3 yet but that test leads me to believe all i frame is maybe helpful under certain conditions, and of course as already mentioned, if storage is not too much of an issue, it may help when you dump it into your NLE.
Jmo, ymmv, yadda, yadda.