Im not so sure about why its not used now, probably because of the raised nose, and the complex aero that's being used there but in terms of it's advantages from what I interpret is as they could be:
1. The sidepods (when viewed from above) look normal, so effectively you have tiny opening = less drag
2. Having the inlet where it is works kind of like early bargeboards, air flowing inside of the barge board goes into sidepod, air flowing outside of it is directed around the sidepod.
To me this is effectively a sidepod working like a sidepod/bargeboard combination. To me the vertical wall of the sidepod from the inlet stretching back to it's widest point appears to mirror a bargeboard.
But that's only my interpretation.
Silence is golden when you don't know a good answer.