You'll have to excuse the slightly spammy nature of this post, but I've just uploaded a video on YouTube of four of the most popular action cameras and their low-light performance.
It's not perfect, and I would redo it (maybe in the Two Tunnels in Bath!) but I've had to send the cameras back now, which is a bit of an arse.
If you guys have any questions let me know. Also, you'll have to excuse my heavy breathing - I had a cold and it's been magnified four times thanks to the mics!