I have more money tied up in Melodyne than I do in Sonar, but I'm taking the wait and see approach for now.
I would be feeling pretty good about a Studio One 3 investment (if I had bought it for $149). I believe Samplitude will be subscription only after this current release. Vegas already announced that it would be.
Hopefully Tracktion Waveform and Harrison Mixbus will continue to improve. I would just assume stay with those two.