QOTD: Use the same device to listen and create?

I used to be really driven to finding the one device that would do it all for me, but recerntly (i.e. in the last year) I've relaxed a lot. Now I'm content to have a handful of devices that do a variety of jobs for me.

I used to try and use a PDA as an MP3 player, but since I moved to an iPod I've become quite happy to have that function as a player and let other devices do their own thing.

Do you listen and create music on the same device, or do you separate them out, and why? Is it important at all?