I would like to throw in a vote to address this. I've been vocal on another thread about X2 never being stable for me, having to revert back to X1, and now not happy about there never being an X2b. I didn't bring it up before, but I've "felt" the instability was related to my Mackie Control Pro, as that was always acting flaky in X2. With X1, it works perfectly...
 
Improved MCU support would get me to upgrade...

Finally, I found Chris Boucher (as you probably know, the programer of Mackiecontrol dll). It turned out he had no idea there have been no updates for 7 years. Unfortunately, he no longer works for Cakewalk, so he can't help us now :( He doesn't even use Sonar any more... But you never know, maybe Cakewalk will eventually get in touch with him (especially after the recent merger with Gibson...). We'll see...

I am curious what will be with our forgotten MCU PRO... Now, it is a very good moment to improve the MackieControl.dll and btw the opinion of Cakewalk's reliability. We will see soon...