equality
What about an update of X2a ---> X2b with that built in stability CW?
Well I'm not a programmer, so I may be totally off base here, but it seems that Cakewalk did a whole lot of work under the hood in going from X2 to X3. If they put the same amount of work into X2a, then I assume they'd have to charge for an X2b update and at that point, it would probably make more sense to update to X3.
The only stability problems I experienced with X2 occurred if I tried to apply V-Vocal to individual takes in Take Lanes, but it didn't happen enough for me to reproduce it. So my fix was just to drag the clip that needed V-Vocal processing into its own track. The other issue was the audio "motorboating"/freeze if I did lots of moving loop points around while Sonar was looping. My fix there was to remember to stop Sonar periodically and re-start when playing back a looped section over and over. Any bug is annoying, but at least for me those weren't show-stoppers.