Specifically...putting it in the EFX bin for real time "general tightening" of a vocal part as opposed to deep vocal correction/obvious effect.  I've been an AT man for many years, but am really trying to go ALL 64-bit plugs for '14...  =)
 
Any pitch correct experts feel free to chime in!  Thanks.

I have not left Melodyne in any project as a region FX because it works best on smaller regions than an entire track. I use it most often for what you are asking but in stand-alone mode. I will open the vocal track (right from the SONAR project folder), hit Ctrl-A (select all notes), apply pitch correction to the key, save the file, and close it. Just be sure X3 does not have the project open when doing that (file sharing conflict concerns). Then when SONAR is opened again it loads the modified file in, and you can continue on your way. This has been my primary use of Melodyne, and my workflow was chosen simply to tighten vocals and "be done with it."
 
While learning the effects that does, it is best to "save as" a different file first, then import it into SONAR so you retain the original (just in case).

Thanks for the reply.  I wish the procedure was "less clunky" than that, as it would be nice to loosen or tighten as needed after hearing the pitch correction in context of the song.  I'll play around with it though...

Melodyne can't do live correction. It's algorithms don't allow it because it depends partly on looking ahead to get a natural sounding result.
 
I completely disagree with the other poster though; I would definitely use Melodyne from within Sonar. ARA integration is one of its best features. If you need it on everything put it on everything. Bouncing back and forth seems a huge waste of time.

I agree with Samderxpander. It may no be a live effect but it's a high quality process. As for the original question, in some ways what melodyne can do is superior to what autotune does. It's a lot more surgical

Sanderxpander
 
 
I completely disagree with the other poster though; I would definitely use Melodyne from within Sonar. ARA integration is one of its best features. If you need it on everything put it on everything. Bouncing back and forth seems a huge waste of time.

Phew, I thought it was just me that can't see the logic to that at all.

Thank you all for your feedback...so my instincts (unfortunately) were right?  Nothing except AT can be dropped in the FX bin for real time tightening?  If only I worked with better vocalists!!!  Including myself...ha ha ha ha

Well if you happen to have jumped on the bandwagon with Addictive Keys recently, you got Nectar Essentials for free last week which can do that I think. I honestly don't really get the point  though. You can't really properly sing with autotune on and for anything else I definitely prefer Melodyne. You can choose to tighten everything or adapt specific notes. I usually do the latter. With ARA it's super, super quick. Select a line/phrase, hit CTRL+M, adjust to taste.

No I mean AFTER the vocalist has done his thing, after I've comped it...sometimes I just put AT in the bin to grab some of the loose notes.  For fine surgery, I've done the graph mode on AT (which has all sorts of issues running 32-bit through BitBridge).  I don't mean live...like in Tim McGraw live at a concert singing through 8 successive AT units... ;)
 
I'll try to get my feet wet with Melodyne.  It's really just fear of the unknown at this point.

Right, well I suppose you could flatten the comp, hit CTRL+M to open Melodyne, CTRL+A to select all notes and then click "correct pitch" with whatever settings you like. I really recommend learning basic Melodyne controls/workflow though, it's really quick and extremely effective.