Uh--Angel--I have in excess of 6,000 hours in the Astar--and many more in other helicopters. The position of the pilot has NOTHING to do with aerodynamics, but more of convenience. The Astar I flew had the PIC on the left because we flew clockwise around an island, and wanted to fit two passenger seats up front to view the island.
We bought our Astars new form the factory with the PIC on the right and then paid to have the aircraft modified for left hand PIC.