Well I bought the upgrade and I have mixed emotions about the result.
 
First off, I have to say the sound quality is very good, according to my ears.
 
Also, I am happy to report that the VST3 version of the CA-2A works just as expected, except it didn't come with any presets. Be sure to look for it under VST3. At first, I couldn't find it since I was looking in the VST2 menu.
 
But there are problems due to the Prochannel.
 
The biggest problem is that the PC4K and the Concrete Limiter only work in the Prochannel.
 
Up until now I have just ignored the Prochannel. I actually ignored the Prochannel so much that I didn't realize what I was buying are not VST plugs. It was a big surprise to me that now I have to use the Prochannel if I want to use the effects I just bought.
 
Part of the reason I have ignored the Prochannel is because I also like to ignore the Track inspector.
 
I ignore the Track Inspector because it offers less information and takes up much more space than the track pane. Using the track pane, you can scan every detail about all tracks. Especially in older versions of Sonar. (they took away the MIDI key change in Sonar X). The track inspector, on the other hand requires layered windows to see what is going on, and you have to look at each track one at a time.
 
I don't think the Prochannel is implemented properly. First, your effects are hidden and could easily be forgotten since Prochannel does not show up in the FX window in the track pane. You need to use the Track Inspector to see the Prochannel.
 
There is no good way to show all Prochannels for all tracks, so you could scan your project's effects. The closest thing is a very hard to look at console view with each track's Prochannel expanded.
 
Next, the prochannel is only available pre or post FX. The only way to put the effect of the Prochannel in the middle of the FX chain is to move your effects from the Track Pane and have them in the FX Chain module inside of Prochannel. This of course hides the whole FX chain if you are looking at the track pane view.
 
Not to mention requiring a complete restructuring of existing projects if you want to use the Prochannel inserts.
 
Cakewalk should have made all of the Prochannel plugs available in VST format. The provided EQ is very good, for example, but is difficult to use because it resides in the Prochannel only.
 
It feels like Cakewalk is trying to force the user away from the track pane and over to the Inspector. Yes the Inspector looks more cool, but the Track Pane is much more effective.
 
Overall, the Sonar X3/Prochannel experience reminds me of my experience of going to Windows 8. (ie "where is the start menu??!!"). For some reason the current generation of programmers are so eager to make a pretty face and implement changes just for the sake of change, that the most useful elements get dropped off or hidden from view. I suppose I am just getting old.
 
One other small problem is that if you buy the Prochannel pack upgrade, it evidently does not come with any presets in which the new effects are used. At least mine didn't. I contacted the email support, but I am still waiting to see what they say about this.
 
But I close with at least one positive thing about Prochannel. It is very easy to save your Prochannel setup for a track. They actually give you quite a few nice chains of Prochannel effects as presets, and it is easy to store your own. This feature is very nice. For example, if you develop a Prochannel for your own voice, you can just bring it into a track with a couple clicks.
 
 
 
 

I think we just have to accept that ProChannel is an attempt to distinguish itself from other DAWs, consequently you have to decide whether you are going to adopt it or not for the reasons you explain.
 
I do think you have some very good points to be made here about enhancing the Pro channel:
http://www.cakewalk.com/support/contact/featurerequest.aspx
 

I share some of your concerns, and then some, but I've already voiced them on here so there's not that much point to reiterate. I will say that if you like the QuadCurve EQ, you will love the Fabfilter ProQ. It works as a regular VST and they have a sale one their bundles right now. The Limiter and Compressor are great too.

I don't. I am a big supporter of the track inspector and Pro Channel. The track inspector shows tons more information that the old track header and widgets could not. A lot of the information was held in context menus before the dual track inspector that first appeared in X1. Plus in order to see all that was displayed before one had to make the track take up more vertical and or horizontal space.  A very clumsy way to present information. Plus not all could be displayed. I use two wide screen monitors and can say that in track view the dual inspector does not take up space that is problematic. Plus it can be reduced with a simple key touch I will collapse it.  Also it can be floated to a second monitor.  
 
Pro Channel is a brilliant innovation that CW has done an amazing job in creating a channel strip that compares well with individual VSTs of high quality without burdening the CPU. Comparing them with VSTs will show just how good they are. 
 
By ignoring one of Sonar X series best features or understand the immense improvement it offers by using the inspector you have hurt yourself needlessly.  
 
   

I'm trying not to get sucked down into this again, but I just want to point out that I personally do like and use the inspector. You were probably responding more to the OP anyway, but just to be clear. I know you all probably can't sleep at night if you haven't had my opinion on this ;)
 
For the rest, I just wanted to plug (ha...ha...) the Fabfilter Pro Q as a VST alternative/upgrade to the QC EQ.

John
The track inspector shows tons more information that the old track header and widgets could not. A lot of the information was held in context menus before the dual track inspector that first appeared in X1. Plus in order to see all that was displayed before one had to make the track take up more vertical and or horizontal space.  A very clumsy way to present information. Plus not all could be displayed. I use two wide screen monitors and can say that in track view the dual inspector does not take up space that is problematic. Plus it can be reduced with a simple key touch I will collapse it.  Also it can be floated to a second monitor.

 
I prefer the current behaviour as well, but I would definitely support what has been suggested if it was made an option in preferences. And maybe have a toggle button, kind of like Maximise/Minimize a window. Nice to have the flexibility.

Sanderxpander
 I will say that if you like the QuadCurve EQ, you will love the Fabfilter ProQ. It works as a regular VST and they have a sale one their bundles right now. The Limiter and Compressor are great too.

NOOOOOOOOOOOOO!
 
Why in the world did you introduce me to this company?
 
I want to spend my money on guitars and women, not software.
 
Now I have to obsess over plug ins.
 
Its all your fault!.
 
BTW, how does their install work? I like the way Cakewalk more or less trusts you. Does Fabfilter have any kind of weird product protection? I avoid software that is over protected.
 
Thanks

Sanderxpander
I'm trying not to get sucked down into this again, but I just want to point out that I personally do like and use the inspector. You were probably responding more to the OP anyway, but just to be clear. I know you all probably can't sleep at night if you haven't had my opinion on this ;)
 
For the rest, I just wanted to plug (ha...ha...) the Fabfilter Pro Q as a VST alternative/upgrade to the QC EQ.

My post was meant for the OP. I'm sorry I wasn't clear about it. 

Fabfilter copy protection is a simple authentication file. Installing and authentication is easy. They have fully functional demos. All of your installation and authentication questions are covered here. If you choose to skip the current sale, you can always get a 10% discount on your first purchase by having a current Fabfilter user send you a discount code.

Also, if you are a student or teach at a music school or something you can get an educational account, meaning your licenses are always 50 percent off but non-transferable (i.e. you can't sell them on).

Sorry for the introduction. They are awesome though. Haven't had them for very long but I'm crazy about the EQ already.