I'd say that it's competitive with older versions of the major DAWs. It's reasonably stable and has a reasonably complete feature set.
The problem for Ardour on Linux is the plugin ecosystem. Any serious DAW user has invested thousands of dollars in plugins, none of which will run on Linux. For Linux to be a serious platform for audio work, it needs much more than just a DAW; it needs samplers, synths, reverbs, dynamics and EQ processors, pitch correction, restoration and mastering tools, etc etc.
Ardour is a noble effort, but I can't help feeling that it's a little bit futile. The sheer scale of the audio software ecosystem seems insurmountable for free software.
The problem for Ardour on Linux is the plugin ecosystem. Any serious DAW user has invested thousands of dollars in plugins, none of which will run on Linux. For Linux to be a serious platform for audio work, it needs much more than just a DAW; it needs samplers, synths, reverbs, dynamics and EQ processors, pitch correction, restoration and mastering tools, etc etc.
Ardour is a noble effort, but I can't help feeling that it's a little bit futile. The sheer scale of the audio software ecosystem seems insurmountable for free software.