Just got a Xiaomi Yi. You can get a script for it that emulates GoPro's SuperView feature as well as increasing the video bit-rate for better motion footage (such as, I don't know, FPV video). This is my first bashing around to see how the SuperView and the higher bit-rate looks. Obviously, YouTube is going to mangle the bit-rate, but what can you do?
Get the Xiaomi Yi SuperView script here: -(Script-Compilation)
Why is SuperView desirable? Because the GoPro and the Xiaomi Yi actually have a 4:3 image sensor. The Yi's sensor is 1920x1440. When you record at 1080p, the Yi simply crops the 1440 down to 1080. This produces an image with the correct dimensions, but it also means that you have less vertical field of view. SuperView uses the whole sensor, which means that you have more vertical field of view, but now you have a 4:3 image, and nobody wants that, so it stretches out the image to fill the 16:9 frame of a 1080p video. So you have some distortion due to the stretching, but everything is usually fisheyed anyway, so who cares? That's the theory anyway.
In practice, neither "regular" nor "superview" is definitively better. They both produce a different effect, and different people may prefer one or the other for different situations. The stretching of the superview mode may not be appropriate for human subjects where the stretching will be more obvious; the decreased vertical FOV for "regular" mode makes the subject look closer (might actually be good for some FPV since stuff looks more intense) and cuts more of the sky out of the frame, which simplifies exposure in some cases.
The above script can be edited to remove the "superview" lines while still keeping the increased video bit-rate, if desired.
Here's a comparison of the GoPro Hero 3 in both modes.