I didn't have time to read the entire thread, but here are my opinions about the issue.
Turbo - not very efficient at low RPMs (point already noted), but can produce much more boost due the the "ram jet" effect. You'll have to consider cooling, fuel delivery, ECU programming.
Supercharger- efficient at low RPMs, restricted by higher RPMs since it's belt driven, can be compensated by changing pulley set ups (still restricted, just better performance with the same RPMs), generally work better on larger displacement engines.
Best- Free-bearing Turbos, a combination of both, where the induction of air would be done by the Supercharger at low RPMs, once the engine is at higher RPMs and the exhaust can spool faster than the belt, the impeller would spin faster and break away from the restriction of the belt driven Supercharger (fiction?). Also cost you beaucoup moolah.