My understanding is that Essential and Editor is one and the same binary, it is just the license that determines which mode it goes into. Which means that if you just installed Sonar Platinum but not Editor, and then enter the Editor license, it will just switch to the Editor version. So whether you update it afterwards via C3 or from the Celemony website, you will really be updating the same thing.
At least this is what I understand, and also this has been my experience so far since I never installed Editor explicitly on my new system, yet it is showing up as the Editor version.