Hi Henrik,
One benefit for me is that I could add my own guitar/piano tracks and they would sync with the metronome in SD3 so I could practice along with them. I don't use a DAW, so this way I could actually record the drum track in SD3 while playing to the song and then export it to my external multitrack recorder. It would be great for people like me who do not use a DAW.
Thanks,
Josh