I use mine for graphics, music, website administration, movie watching, music practice and teaching preparation. And I don't have the collection of rack hardware with me at the moment but when I do, I'll need to set all the MIDI connections and patches up within the DAW in order to access them via a keyboard or MIDI bass or whatever. So, like you, I tend to see the PC as a job for recording the bones of a piece once the framework is done rather than something for trying out ideas for a framework as they happen. But unlike you I don't have the experience or skill to form songs in my head. I need to externalise it first.