GoPro Hero 6
 

Picked up a Hero 6 today and will try to find some time tomorrow to shoot some footage.
I have firmware version 01.00.
The image stabilization looks decent but when I did a crude test against the Sony FDR-X3000 action cam with the BOSS, the Sony held up better. Stabilization is not available in the following modes:
4K 60p, FHD 240p, 2.7K 120p.

Bit rates, for anyone who is interested (I didn't check them all, just some I'm interested in for now):
4K 30p = 67.1Mbps, 4K 60p = 65.4Mbps, FHD 120p = 66.3Mbps, FHD 240p = 81.8Mbps.
Compared to Sony FDR-X3000: 4K 30p = 98.3Mbps, FHD 120p = 99.4Mbps.

The high frame rate files are saved at their selected fps and audio is recorded. Uses same battery as Hero 5.

Attached are some details of file data.

EDIT: The new HEVC (used for 4K 60p and FHD 240p) are not recognized in Sony Vegas Pro 13. Magix VP15 recognizes them. Premiere Pro CS6 recognizes them as just audio files.