I have one, it's a ton of fun but it's only good for what it's good for. In a traditional cinematic sense there's no way it replaces a cinema camera with interchangeable lenses, manual settings and a large sensor.
What it's great at: aerial stuff, Landscapes, timelapses, action and vehicle shots, documentary and hidden-cam type footage, and anytime you want a low-risk "disposable" camera for shots too dangerous for expensive cameras.
Why you shouldn't use it as your A-cam in a narrative- you have no control over brightness (gain/iso and aperture) or shutter speed, it's extremely wide angle and distorts the image (like a fisheye lens). Because of it's wide angle if you want a tight shot you'll need to be a foot or two from the actor, and then they'll look funny because of the distortion.
As far as audio capture, don't even think about it using it for legit audio. It does capture reference audio which is nice, but unless you're doing some reality type thing you'd still need a real audio rig, and because it's so wide if you don't want to see your microphones they will have to be really far away or use hidden wireless lapels.
If you already have one and no money and want to make a movie by all means shoot with what you have, but if you're looking to buy this for a narrative movie there are better options.
Edit:
And yes, it does make a great image. In the higher resolutions and frame rates it can only be full wide. The "medium" and "tight" modes are essentially just a cropped off part of the sensor and force a lower resolution.
Just to reiterate, this camera is a lot of fun though. I've stuck it on cars and hidden it in shots. The iPhone app to control it is very handy. I'm taking it kayaking next week and sky-diving this summer. Again, that's the stuff it's made for.