Are there any advantages to use .au versions plugins over .vst on OSX ?
Are .au Better on CPU ???
I don't know if there is a difference, but I use VST so that I can open the projects on either a Mac or a Windows computer, as long as the plugins are on both systems.
I prefer VST over AU, because the later has no MIDI output, which is helpful, when using ARP plugins for example to record single notes to a new MIDI track.