well, to be frank... shoulda jumped; quite a deal...  
I really didn't use X2 that much as lots of other stuff was happin' in my life, but as far as I'm concerned, COMPING is now the "bestest coolest most awesomest tool ever!" to quote my 13 year old, if she were here...she watched me and just sat there and said, WOW!!!!!!!! and WOOOO and "that's amazing!" as I popped up different vocal vamps, re-swiped the region to redefine it....

Comping is huge. If you do comping, Sonar now has the best.

VST3 support would hit the list as well. X3 was the first version I purchased external plug-ins for, and decided on the iZotope Studio Bundle, so the VST3 support was a nice to have (although those plugs are scripted at all levels, which gave me a lot of respect for iZotope).
 
X3 by itself is worth the upgrade, IMO. The extra "goodies" are just icing on the cake for me.

X3 Can't Do Withouts?

 
More updates/fixes than ever before.

Looks like the verdicts in.  I'm glad to hear it.  If felt disappointed a few times with the early upgrades, but now I feel I may I missed out on a deal.  Way to go, Cakewalk!  I knew there was reason I stuck with you all these years.

Can't do without X2. I have to do everything in X2 and I only use X3 to finalize mixes since it's an eyesore. It is superior to X2 in every way except legibility. Without Panup's mods, I would not be able to do without 8.5.

http://www.cakewalk.com/products/sonar/web-trial.aspx
 

Cactus Music
I see a nice piece of recording software that does everything I need, well except wave editing.

What specific wave editing functions would you like to see? I'm taking notes

Anderton

Cactus Music
I see a nice piece of recording software that does everything I need, well except wave editing.

What specific wave editing functions would you like to see? I'm taking notes

Noise Reduction like Audition.
Sampling and slicing like Geist.

On my cell, sorry for the curt input.

Cactus Music
I guess it is only a matter of once one has been working with a dedicated wave editor, you find other audio software very lacking in these features. 
 
Simple things like cutting out a little tiny spike using the mouse instead of 6 layers of menus to get at the "gain" menu or using nodes and automation. 
 
Sonar also seem to not have any global analyzing  features, like RMS level and real Normalizing. Once again if you have used these features in software like Wave lab, you'll see what I'm saying.

I guess I wasn't clear, I was more interested in the functions you wanted, not the workflow...separate topic. For example you mentioned gain and EQ, what would be (for example) your Top 10 items you'd want to see in that context menu? (I assume by "cutting out a little tiny spike using the mouse" you mean a pencil tool?).
 
One thing I have noticed about Sonar is somewhere along the line it seems they started including crossfades for areas where you've applied DSP. I often apply gain changes to part of a file and wonder how I get away with it   It was also a happy day when Wavelab added that, and Sound Forge gave control over the crossfade times.
 
Noise reduction...I've often thought that would be helpful as well. It's the one remaining function where I often open up audio in Sound Forge and use its noise reduction.
 
As to analytics, yes, most DAWs are lacking in analytics and Sonar is no exception. But again, what are the main analysis algorithms you'd want to see in addition to RMS level and "real" normalizing (I assume you mean normalizing based on average rather than peak levels)? Trying to turn Sonar into something like Sequoia is about the same as expecting it to do video editing like Vegas (or Vegas to handle multitrack audio as well as Sonar). But maybe it would be possible to incorporate some of the most important functions into a future version.

Thatsastrat
+1 for the wave editing right inside the Daw. Be able to knock down peaks so  when you put a compressor on it, it will behave a bunch nicer. Be able to do entire clip gain or clip reduction with a visible change to how the wave form appears. I will also add that I would love to see a mastering solution like Studio One where you can assemble your tracks, rearrange them if you chose, apply final effects, and any changes done to tracks outside of the mastering solution would be updated back into the mastering project. Is that asking to much? You have the power Cakewalk.

Yeah I mentioned the mastering in S1 on another thread.  I had a throw away copy of artist and I took advantage of the $99 upgrade to professional on Black Friday for that feature alone.  S1 really has some great features, but lacks in some others (MIDI support is average at best). But I love their mastering suite.  I would love to see something like that in Sonar where you could change track order on the fly, and do entire album mastering.
 
Also I love the S1 home screen, and I'd love to see CW update the home screen in Sonar, seems like it's been basically the same home screen for several revisions.  But having a home screen that has instant access to your projects, interface settings, access to sound cloud, and a built in news feed.  Imagine that, advertising the product within the product itself!
 
I have to say though, I always thought "Studio One" was a stupid name for a DAW.  Now it's "Studio One 2"  and with the upgrade it's "Studio One 2.5".  Not sure how well they thought that one out, but it could have been worse.  At least they didn't call it "PreStudio".