As said the valve placement of the Hemi is superior as the valves open away (not parallel) to the bores for a better flow window. In terms of port efficiency only a 4 valve hemi can be better.

The downside to the Hemi has always been the comparatively heavy piston needed to fill up the chamber for high compression (not an issue in Blower motors) and it's heavy/complex (and not very mechanically efficient in terms of rocker ratios) valvetrain.