First a thank you for this thread, it's been among the most useful for those of us choosing to move out of Sonar at this time. My choice is Studio One. After demoing both S1 and CBase (the similarities are striking), I just prefer the idea of the fresher code approach found in S1 over the legacy in CBase. Mind you I have used Cakewalk since the midi only days of MSDOS (I just dated myself) and should not be concerned with older code but if I'm moving on, then why not with modern programing. I believe however that either is a viable choice for any Sonar orphan. While there are a few Sonar specific functions I wish existed in both programs, I'm hopeful that the new base of former Sonar users now in other DAW camps will carry enough weight to influence their future development.
I am handling the transition by loading S1 onto a second 1TB internal drive on my system, keeping it full segregated from my current SPlat projects. I will continue to use Sonar while learning S1. Once I've reached a comfortable level of proficiency, I'll begin to transfer my projects over from Sonar into S1, and as a safety measure, start with the simplest and least important ones first. I will of course fully archive all of the work I've done in Sonar and keep a functioning copy on the other internal drive for as long as possible.
Best efforts and results to all Sonar users in moving on.