I installed the trial version of Pre13 and went straight to testing the stabilizer. What an improvement! It has smoother stabilization and a better interface -- a whole different adjustment control.
In prior versions, if you rendered previews on stabilized regions, the rendered previews would be missing the next time the project was loaded, necessitating another round of preview rendering. Now the previews are still there when you load the project the next time.
That's all I've tested so far, but I did notice better performace. In preferences, if you have Intel HD 2000 and above graphics, you can select an option to use it for acceleration.
I can upgrade to PRE13 for $79.00. Amazon has it for $99.00.