Here is a quick test I threw together of Pilotfly H1+ in "invert mode", GH4 with Rokinon 7.5mm lens, with and without fisheye plugin removal. It is amazing what software can do! I am posting this because I know many people like GoPros and fisheye removal can help when the widest field of view is used.
There is noticeable up/down walking movement; the Pilotfly people gave me some settings to try that should help. I'll try those and post up later.