Indeed very poor dynamic range, the highlight roll off is one of the worst, not sure if this is hero 4, hopefully not.
Similar to Twixtor
a7rii will have moire in fullframe mode not in s35 mode(cropped)
a7rii will have some moire in fullframe mode not in s35 mode. A7s wont in fullframe
120fps is a full sensor readout
A7Rii: 42 Megapixel sensor(more detail), iso 800 for slog(easier to use)
A7Sii: 12 megapixel sensor(better low light), 1080p 120fps(better slow mo), Slog-3 (better grading)
Those are the big differences in general. It really depends what kind of shooter you are