With C 41 negative film, the colors always need to be corrected, and for scanning, the mask must be determined properly.
Therefore a C 41 film may look horrible, may be made to look horrible, or presented as the wonder it is. It is not all in the negative film as it is on a slide! A set of skills is needed to extract even good results.
So all comparisons as above just show that the scan/adjusting process for Ektar 100 are still insufficiently mastered by the cyan posters, etc etc. Just keep trying and we shall see the wonder of this film ...