It's extremely limited at what it can do. To me, it's totally useless, as everything I do is 90% MIDI. But I guess it's better than nothing.There are open formats. Just like there is AATranslator for converting project data between DAWs.
I do like Ardour a lot. I didn't mean to criticize it as being a bad DAW. What I'm saying is that without thorough Windows VST support, it's not going to be used much.