No doubt, even the EDIUS chromakey effect will deliver good results if there were optimal conditions at the shoot. But in reality most of the shoots including green or blue screen are not performed under ideal conditions.
You will only get to know a chromakey's quality if you have footage that was not produced under best conditions or if you have very complex motifs which contain transparency and reflections. Since in reality often there is less time and space to set up a perfect light for a blue or green screen you will have to deal with the mentioned difficulties in your footage.
But due to the background color even the perfect light many times can't avoid blue or green outlines being visible at a person's hair or head. Additionally there can be problems with light reflections in a person's glasses and color changes if the key colors shine too bright.
"We'll fix it in the post" does not always work out in such cases. Although the EDIUS chromakey does good work - in real-time - it can not be the solution to very complex keying problems.
Furthermore the EDIUS chromakey has some technical limitations. Unlike a color correction filter, the chromakey affects the alpha channel of a clip and therefore cannot be combined with other filters or effects.
With Robuskey there are no such limitations and you will have a lot more options to edit your footage. Robuskey works as a filter/effect and therefore can be adjusted individually. This way it is possible to apply a primary or secondary color correction on the footage without affecting the actual keying result.