Cakewalk bought the Roland hardware (vs700C & vs700R) in 2008(?) and integrated its Sonar software with that hardware.  The problem I see is with a proprietary serial link Roland instantiated between the control surface, vs700C and its separate IO interface, vs700R.  Am unsure of the protocol and never tried to instrument/analyze it.  Between the IO interface and the PC is a standard USB serial link.  In my case, I had PC Audio Labs build a dedicated PC with RAID drives and a lean OS (Win 8) which I will not upgrade because of compatibility issues with Sonar 8.5 and after reading about quirks like the OP and others have mentioned.
Have had lots of issues using vs700/Sonar, but mostly due to pilot error on my part: understanding input/output/side-chains of modules, configuration for tracking verses mixing, keeping track of sample rate (both hardware and software settings) from project to project, processor intensive apps versus taking advantage of built-in hardware synthesis, etc.  If I had to start over, now in hindsight, I would choose Pro Tools with a more generic control surface and IO interface, but as someone here mentioned, if you can make use of your vs700C, and it improves your mixing workflow, keep it. My 2 cents.

I have the Mackie Control Universal (MCU) and it works tight with Sonar Platinum.
 
It's been the go to controller for Sonar since it was made, however, you must read the instruction in Sonar on how to operate just for Sonar.
 
First, open the controller / Surface properties box and then press F1.  There is a hidden menu area in Sonar just with Help pages for the Mackie Control Surface.  It provides all of the instructions and the settings for Sonar and the MCU. 
 
The original MCU is no longer available, however, Mackie makes a MCU Pro now.
 
Check out the video explaining the MCU
 

Looks like I'll be sticking with my fw1082...it works great with sonar, but I just came to see if anything has come along to make me consider upgrading/replacing it...
I see no need to upgrade to Windows 10 from 7...
Just seems to mean than when I finally am forced to, I'll be upgrading everything... At that point maybe I'll be willing to go full touch screen....

One day touch screens with the new gorilla glass laid flat may become the new "controllers" ?
*I'm looking at a controller for the first time, and that thought keeps popping into my head. Maybe the displays won't overcome the need for the "feel" we look for in a fader,
or pads, buttons, etc, but imagine a large screen that can be written on, cleared, profiles saved, easily illuminated for stage use, etc.

Just a thought. It's early, maybe I need more coffee 😉.

Rob[atSound-Rehab]
As regards the OP ... the vs700 is still the best you can get when using sonar. I was just as shocked when they dropped its support so quickly but mine still works fine here. It has far more control features than any other available CS and I even extended its functionality by assigning features to unused key combinations via MIDI translator

My advice - hold on to vs700 if you already own it. There is nothing better out there for sonar ... and cakewalk is totally ignoring any CS functionality requests. So nothing will change here.

My problem with VS700c is that half the controls on it no longer work. My jog wheel does nothing, Access panel does nothing... forget about surround and misc other buttons... the only thing it really does is basic transport and console functions.

TerraSin
My problem with VS700c is that half the controls on it no longer work. My jog wheel does nothing, Access panel does nothing... forget about surround and misc other buttons... the only thing it really does is basic transport and console functions.

that's an awful lot that is not working - especially since it's only Mackie control stuff, which still works. it makes me wonder if the required *dlls that sonar needs are still all there and functioning or if maybe the setup inside Sonar got corrupted somehow???
 
Have you ever tried to intercept the MIDI messages which the vs700 sends to see if all the buttons are still working i.e. sending messages? That's the first things I'd try to determine if it is a hardware problem or not. Hook up the vs700C via USB to exclude any issues the VS700R could have. Then take any MIDI tool that can listen to the ports and print the messages it receives and see what the non-functioning vs70 buttons send ... report back or PM me if I can help!
 
As said above - mine works fine with latest Sonar Platinum (apart from the master fader often staying at -INF which is something it did not not do 2 years ago, but apart from that all is OK used in every session I do)

dwardzala
There are several threads regarding the X-touch.  I bought mine about a month ago based on those.  The set up was very easy and the controls, while not labeled correctly for Sonar (or Reaper or StudioOne) on the unit, are very useful.  A template or overlay can easily remedy this.  I have had nothing but good results with it.

Note that the MCU Pro comes with Lexan overlays for a bunch of DAWs, including SONAR. Nice!

In my opinion if Cakewalk wants SONAR to be more popular, they should do two things:
1: Make a nice professional looking control surface
2: MAC compatibility
 
And number 1 is more important because without it, the professionals don't take CakeWalk seriously.
Look at "Studio one", "nuendo", "protools", "logic" with their own hardware and then sonar with poor and limited hardware support. I love SONAR but .............

sarmad_dehnadi
In my opinion if Cakewalk wants SONAR to be more popular, they should do two things:
1: Make a nice professional looking control surface
2: MAC compatibility
 
And number 1 is more important because without it, the professionals don't take CakeWalk seriously.
Look at "Studio one", "nuendo", "protools", "logic" with their own hardware and then sonar with poor and limited hardware support. I love SONAR but .............

1. Have you seen what happened when someone has tried to make professional control surface for Sonar? Cakewalk was sold (and you can find corresponding financial status on Roland sites...)
2. They have tried with MAC version (what is modern MAC? it is a PC from one assembly company with a proprietary OS). There are many discussions about the topic.
 
If you love Sonar, why you wish it disappears?

Rob[atSound-Rehab]
Have you ever tried to intercept the MIDI messages which the vs700 sends to see if all the buttons are still working i.e. sending messages? That's the first things I'd try to determine if it is a hardware problem or not. Hook up the vs700C via USB to exclude any issues the VS700R could have. Then take any MIDI tool that can listen to the ports and print the messages it receives and see what the non-functioning vs70 buttons send ... report back or PM me if I can help!
 
As said above - mine works fine with latest Sonar Platinum (apart from the master fader often staying at -INF which is something it did not not do 2 years ago, but apart from that all is OK used in every session I do)

Yup, all MIDI is sending and everything is working. I only use the C as I've retired the R so it's all hooked up via USB. Not sure why a lot of it isn't mapped properly.