as captioned.

yes. its a newer version with more options.
http://helpcenter.celemony.com/hc2-content/melodynestudio4/en/m4_updateinfo_v4.1.html?edition=melodyne-studio&docTypes=anleitung~tutorials~tipps-info&lang=en&sort=RELEVANCE&grouped=false&query=&showStartPage=true#New-functions-and-improvements

I think Melodyne Essential 4 was a free update from 2, regardless of Sonar version, or indeed independent from Cakewalk at all. So in that case, no, you don't get more/better Melodyne by upgrading to Platinum. Plenty of other reasons to upgrade though, and Melodyne as well.

Sanderxpander
I think Melodyne Essential 4 was a free update from 2, regardless of Sonar version, or indeed independent from Cakewalk at all. So in that case, no, you don't get more/better Melodyne by upgrading to Platinum. Plenty of other reasons to upgrade though, and Melodyne as well.

Even with Melodyne 4 as an upgrade on the essentials side.  X3 does NOT have the ability to drag a clip to the time line and create a tempo map from a clip like Platinum does.
 
SInce that function is tied to Melodyne, I would say yes, Melodyne related features are available on the upgrade to Plat.  

Good point!