I can see taking a slow, methodical approach to moving on, but I don't see the point in hanging on and on and on.
I've dipped my toe in the Reaper pool a few times over the years and finally committed to working thru the niggles last year. I'm VERY glad I did that. I also grabbed SO3 Pro last year and spent time getting to know it.
For now, I'm moving to Reaper. I guess I already did a few months ago, to be honest. I'll also keep SO3 up to date on the sidelines to see how it develops over the next year or two or three.
SONAR will be kept on life support in some fashion until I'm pretty sure I have stems and other important bits of past projects available for importing into another DAW.
I feel for those of you that have a revenue stream dependent on a SONAR based studio you've nurtured for many years. That has to be hard to swallow right now.