I guess exporting the song to midi is the obvious way. To import the midi file into a DAW is in most cases very easy, but to set up the instruments (VSTi) can be quite a task. I would like to have the alternative to export each track to a separate wav file. By that you are still able to add specific effects and levels but don't have to be a detective finding out all the each instruments patch (which must be saved/exported) if you have tweaked them while composing.
To import wav files into a DAW would in contrast be a rather fast process. Some DAWs even accept drag and drop of multiple files and creates tracks accordingly.
Maybe an option to select which tracks you want to export would be useful if you halfway in the mixing process go back in to the composing phase to tweak one or two tracks. No need to export all tracks again as it probably would time consuming process.
Yes, there is a work-around to achieve this today by muting all but one track but it's really not fun if you have more than 3 tracks... it just ain't Rapid anymore
