There's been some comparisons between the GoPro HERO 4 and the Sony FDR-X1000V, and you can find them on YouTube, but for me, the colors were better.

X1000V/W 4K Action Cam would be a good alternative to the GoPro Hero 4 Black edition (they both retail for the same price).

like this will be sold on eBAY real soon and a GoPro Hero 4 will be on the horizon

After having used the GoPro Hero 3+, I was anxious to upgrade to a 4K camera, and thought that the Sony FDR