what's the limitation of Melodyne? I've got X2 and cross-graded to Samplitude ProX (instead of upgrading to X3) loving Samp, after using the plugins in it never have a hankering for any of the X2 pluging except for the Softtube plug, samp has a tube plugin but it's not all that good. As far as the LP stuff it blows away the LP e.q. and comp. in sonar. Anyway I'd have thought that Melodyne was better than the stuff in Samp, for pitch correction, maybe you do have to have the full blown version of Melodyne though.
Maybe I'll See what Sonar x4 has to offer when it comes out,  for now it's all Samplitude (though I do still use dimPro and Rapture and it's nice to know I have two options of DAW to use if I need to)

The version of Melodyne included in Sonar is Melodyne Essential, which normally costs $99. It does basic pitch and timing correction as well as pitch transposition for monophonic signal sources, and also surprisingly impressive audio-to-MIDI conversion. Melodyne Editor is more like V-Vocal on steroids.
 
People seem to focus on the plug-ins in X3, but to me the huge features have been VST3 support, ARA integration, and the incredible comping improvements. 

Doesn't sound like the Samplitudes Elastic audio does anything that Melodyne Essentials doesn't do. Yeah, I don't see any need for any 3rd party plugings for samp, sure some of the more unique ones would be nice but def. not needed. One of the other things that I do miss that Sonar has(which at first I actually didn't like) is the track Icons, It is quicker than just names.

One of Samplitude's strengths is it's Object based editor.
A Samplitude "Object" is equivalent to a "Clip" in Sonar.
Samplitude offers a lot of control in the Object Editor.  
Advanced fade-in/out curves, swapping L/R channels, flipping phase, EFX Sends, EFX inserts, gain control, etc.
It's kind of the ultimate in "Snap-shot" style automation.
With this level of control over each clip, Samplitude makes a particularly good Mastering Environment.
You can layout each tune... with advanced fades and/or cross-fades, add any necessary processing to each individual tune (completely non-destructive/realtime), add track indices to Object borders, and burn a CD.
 
For hardcore slice-and-dice type editing, Samplitude is hard to beat.
 
Most of these things can be done in X3... albeit in a slightly different manner.
 
While vari-audio is nice, it's not nothing on Melodyne.   

Jim Roseberry
Most of these things can be done in X3... albeit in a slightly different manner.

Agreed. I reviewed Samplitude at one point and really got into the object-oriented editing. It inspired me to do a lot more object-oriented (clip-based) editing in Sonar once I saw some of the advantages.

Yep, I remember adamantly requesting "Clip based processing" for Sonar.
That opens up a whole world of possibilities.
Aside from "Mastering", Clip based processing is a great tool to de-essing and removing/diminishing plosives!

With you already owning a version of X3 - the upgrade shouldn't be too painful. As others mentioned here, Melodyne Essential is included in Sonar X3 P - fully licensed and works great for monophonic tracks. Upgrading to the Editor version can be found for under $150 quite often. Audiodeluxe.com had it as low as $109 in the past few months.