I think I'm going to hold off for a bit, see what fixes come out...

I upgraded Editor 2 to Studio 4, and immediately had Sonar crashfest  opening any project with Editor 2 clips.
I quickly discovered the issue was with my control surface renaming the VST3 file, and once I removed that from the VST scan path everything worked as expected.
 
I've been using Studio 4 daily for a few weeks, and have had no further issues with it, and am really enjoying the new features they've added. New pitch detection algorithms, EQ/Harmonics sound editor, tempo detection, saving templates, multi-track editing of harmony vocals.
 
I actually find the possibilities of Studio 4's audio manipulation and repair astounding. What blew me away the most was just as a test, I opened a stereo wave file (in standalone version) recorded over 15 years ago. The musicians and hardware from those days are long gone, and remixing individual tracks was not possible . . . but I was actually able to locate and turn up a few vocal parts, get rid of some bass clutter, re-EQ some sections, play with the tempo . . . export it as audio, put it back into Sonar, apply some mastering plugins. Poof.

Isn't Essential 4 to Editor 4 just $99. I got Studio 4 for $126 so $400 makes no sense..
I think it is the same as was for Melodyne 2.

Hey mmarton.
I was on editor 2 and tried to get the demo of studio 4 to activate but was only able to get it to open in player mode. I took a chance and jumped for the studio 4 update. I have been using it for a couple of weeks now without any issues. The multi-track view is very handy when tweaking backing vocals and the sound design features are pretty sweet too. For me the $149 upgrade path was a steal, but there is no rush. I believe it is available at that price until the end of March.

tenfoot +1.
Studio 4 is working fine here.

"fixing" vocals with tools like melodyne is way overrated and overused IMHO. even though i own it and have to use it occasionally, i stay clear from it as much as possible because tampering with the tuning simply changes the character of the performance. no matter how good the correction software is. period.
 
the way a vocalist gets to a note or off a note is what makes him/her distinguishable from the rest (which all starts to sound the same in recent years). if it needs too much fixing, ditch it and re-record. have the vocalist practise. give them him/her some coaching because even if they have been "singing" for years, they may never have heard / perceived themselves the way a producer does.
 
finally, go dig out some recordings from the pre pro tools days. not everything is perfect when you listen to the detail, but the vibe and performance are great!

I went from Editor 2 to Studio 4 and am happy to report it's working like a charm for me...no crashes, or stop working stuff. It's a very smooth piece of software with some added things to play with. I recently had to take a song up by initially one and a half tones and I had recorded a guitar. I didn't want to redo the guitar so I tried S4 and it worked beautifully...I later had to take it up another tone and again no probs. I wouldn't have dared to do that in E2 as it always felt unstable and unless you did that and then mixed down, it was risky leaving it open...not so far with S4. Good job Celemony! +1

I have Editor 2, and I'm on the fence about upgrading to Studio 4.
 
On the one hand, I'm reading here and on KVR about crashes, confusion about new version overwriting the old, lack of changes to the core algorithm, missing features, and problems reaching support. On the other, the professional reviews I've read (especially on Sound on Sound) have been extremely favorable. In the SOS review, the only Con about the ARA Studio version was about lack of automation for Sound Editor parameters. Also, Celemony has been responsive by publishing an update to fix bugs.
 
I've read some of the information on Celemony's Help Center, but it would be easier for me to make a decision if I could read the manual. I couldn't find a manual to download on the Celemony site, and I've read that there's no big manual available in the installed version. Is that right? Maybe I just need to spend more time with the Help Center.
 
I'm glad I have until the end of April to make a decision.
 
Mitch I.

went from Editor 2 to Studio 4 & it is working good for me so far, no crashes (but i don't leave Melodyne clips in my projects; i always bounce to clip, so i would not have problems with Melodyne 4 trying to open up Melodyne 2 clips)

Well it's good to see people with no issues...I'm not a power user and most upgrades of software and plugs I've never had issue with so I may go ahead anyways...the new features seem really awesome...