We were not expecting a contest between the Sony A7s II and FS5 for low light. The FS5 results seem okay but not as good as we were hoping for. We would use the FS5 for up to about ISO 3200. The 100Mbps in 8-bit 4:2:0 color is still offensive to us given the price of the FS5 and we cannot wait for 10 bit color to become common for 4K video recording.
This second video compares the Canon C100 Mark II (which does not do 4K) to the Sony FS5: