You are welcome.
If you don't want to spend any cash on this right now, definitely keep Editor 2.
If you don't want the Essential 4 red light nagging you in Cakewalk Command Center, just right click it and choose 'hide'.
People who never upgraded to Editor 2 will not lose anything by an upgrade to Essential 4 so go for it in this case..
If you have upgraded to Editor 2 DO NOT upgrade to Essential 4. It will overwrite your Editor 2 and you will have to reinstall then re-authorize Editor 2.
 

Microapp.
I have done that. Thank you.

Thank you, Microapp!

Thanks for the info.   I have a full Studio version of  Melodyne and seem to have constant problems with the free version supplied with Sonar trying to substitute itself for the full version.    At the moment, with Melodyne 4, nothing works!    Hoping to resolve soon ...

Very helpful info. 
 
Microapp, do the  Melodyne 4 Studio features work within the Sonar ARA integration?  I have Melodyne 2 Editor and am about to upgrade - and the ARA integration has been a huge workflow plus.