Peter,
the advantage of the GoPro (and similar) is that it's got a wide angle lens and the picture quality is much better when attached to the outside of the plane. Also the cockpit reflections in your video are a constant problem. The GoPro is able to mostly eliminate the propeller effect. I can also position it in a way that the propellor is not visible at all.
The NFlight aviator lens removes the prop distortion very nicely
How does it work?
the picture quality is much better when attached to the outside of the plane
Of course 
I did consider mounting a camera externally, by making a thin sheet metal bracket which would pass through the door seal. The suction cups would be on the inside of the window but the camera would be just outside the cockpit.
However I think the biggest "quality factor" in flying movies is flying low. All the time one is flying high (a few thousand feet or more) one has issues with haze - unless one picks an unusual post-frontal day. Looking at all the really good movies out there, they were shot at very low levels.
The NFlight camera (model 1100 if my memory serves me right) has an "aviator" lens filter fitted. I am no camera expert but I am told this is the equivalent of an ND4 filter
I played a lot with various ND filters - bought a load of cheap ones on Ebay - with a camcorder which did not have a manual shutter speed.
They definitely help but I was never able to really remove the prop. Not in bright sunshine.
But it must be camera dependent. I am sure these people get plenty of customer feedback, from GA applications.
The prop effects are "fun" for about 5 minutes but one quickly gets tired of watching them. I would say the same for wide angle (with distortion, as most of them are) but that's a personal thing
I would say the same for wide angle (with distortion, as most of them are) but that's a personal thing
The GoPro Hero 2, at it's highest resolution, can record at wide, medium and narrow angle. I don't know the exact angles and the way the medium and narrow angle is produced, but it does make quite a change when you film objects that are a bit in the distance. And you get less of a fisheye effect in the recording.
The NFlight Cam is 111degrees in full HD or 135 degrees in 720 mode. I especially like the rotating lens which makes setup much easier. And yes, a scimitaring prop is cute for about 1 nanosecond.
Hi Achimha, did you use the GoPro adhesive, that comes with the mounts? How can it be removed after usage without damagint the aircraft's paint?
ch. winter
Heat should be enough to remove the adhesive. You can use a heat gun.
For Boscomantico, this was taken with the NFlight camera - look - virtually no "prop strobing".
For those of you who might want to buy the Go Pro, look at the Hama HD Star, I bought one and am very happy, it has pretty much the same specs as the Go Pro2 but has a few extras - for example, it has a laser pointer so you can see where the center of the field of view is, secondly it came complete with underwater casing and also the detachable screen. The only thing it didn't come with was the suction mount but I had one from a Go Pro lying around and yes, it fits......
However it has the same restrictions as the Go Pro - Prop artifacts, also poor white balance but as that's a trait of all these mini cameras that I have seen so far, I'm not too bothered - mounting an HD Camcorder on a tripod securely on the back seats is a bit of a kerfuffle so mounting the camera on the window using the suction mount is the best compromise - after all, who wants a video of their instruments??? Maybe one day I'll suction mount it to the outside ;-)
an example video is here, don't forget to select HD resolution. ;-)
