OM-D seems to have a slight image advantage over the GH3

Based on the comparisons in the GH3 hands-on preview.   In the RAW format, there seems at various ISO's to be greater resolution in the studio shots from the OM-D and perhaps a half-stop better noise control.  The GH3 images were slightly darker-looking.  I don't know if the resolution difference was due to the lenses used, however.