Just gonna update:
I bought one of these a couple of days ago. I was just about to pull the trigger on a camera when Dave posted this.
The choice wasn't based on stabilization, more on image quality and the ability to use external mikes, etc.
The one I got was the "Creator's Combo" which is really necessary, IMHO. Without it there's no WiFi, no mic input and you're forced to attach it to your phone via a flimsy USB dongle which looks like it could break at any moment (yes they sell brackets to support the phone next to the camera but you still have to take your phone out of its case and the whole system is terrible).
The Creators Combo costs more but it has a lot of useful stuff in it: Wireless mic, a little tripod, wide angle lens, mini joystick, plenty of stuff I'd also have to add to a GoPro anyway if I went that way and would probably cost more overall than the DJI.
Anyway: I made the decision based more on image quality, it hasn't disappointed in my tests. It's also a 64 megapixel still camera whereas GoPros are useless for stills.
On the plus side, I've discovered a whole bunch of stuff that I hadn't thought about, eg. The gimbal doesn't just work for image stabilization, you can set up the camera on its tripod and pan it around remotely from your phone.
Most reviewers complain about the case but it's very well thought out. eg. The screw hole that they all shrug and mutter over is for actually for carrying your tripod around. The hole at the other end it for attaching the wireless mic. The wide angle lens has a little magnetic clip inside it, as do the USB dongles.
Bottom line: I'm pleased I got it instead of the GoPro, although I think the GoPro is still a far better choice if you want to attach it to a skateboard and abuse it.
Edit: Here it is in the case with all the toys attached.