He doesn't mention MIDI. He wants mixing, audio editing, and stability.
Are you suggesting a viable alternative to Ardour exists? I'd be very interested.
I don't care about MIDI, I just need a DAW that does the sorts of things ProTools does. Cut and paste audio, fly regions around, set up busses and sub groups and VCA groups, apply plugins, do fader automation. An actual DAW, not a Fruity Loops clone or something. Sounds like this is what the OP is looking for as well.
If such a thing other than Ardour exists I've never seen it.