Whats good for Flyfishing you ask?
16.5 megapixel small form factor Mico 4/3
4K VIdeo which gives us better 1080P in a 10bit 4.4.4. color space
1080P 60 to 96 fps overcranking for awesome slow motion in 1080p without Twixtor
Better and faster autofocus tracking in Video than GH3
Bettter brighter Screen OLED for outside use.
12 stops of Dynamic Range for those evening lowlight hatches Super ISO 25600 setting.
Great HDR functions and in camera filters.