Two things wrong in Sonar x64
1) The valve type buttons don't light up, so you have no idea whether it's 'taken' or not, and no confirmation of what's working.
2) Automation doesn't work. It writes but doesn't playback or bounce. This is stupid. It's a known issue in the Native Bundle and Soundtoys have refused to address it for over six months. "The issue is quite involved and will take a considerable number of cycles from one of our programmers so it will not be anytime soon." says Mitch.
Now it appears that they've built a new plugin on the same architecture that's already known to fail in 64bit hosts. My bet is the Autopanner will live down to the same expectations.
Compare this attitude to other VST developers like Spectrasonics, Softube, Camel, PSP, NI, EWQL Synthogy and Voxengo (a one man outfit) and it's easy to see who really cares about the userbase.
Sorry, Mitch.