If you compare the Sony RX0 and GoPro Hero 6 at most tasks the GoPro Hero 6 is going to win if the environment is well lit, but once the light is reduced the Sony RX0 clearly pulls ahead. Even though the Sony FDR X3000 is designed to be the GoPro’s natural competitor the RX0’s form factor begs for them to be compared, which is why vlogers/bloggers keep comparing these two cameras.
Sony RX0: B&H Photo / Amazon / Adorama
GoPro 6: B&H Photo/Amazon/Adorama
Sony FDR X3000: B&H Photo/Amazon/Adorama