I don't have a side-by-side comparison for you. The videos I saw, I didn't see much difference either. But since the hack was free I installed it. I notice much less noise in shadow areas and less or zero compression artifacts in things like movement over asphalt, leaves on trees on a windy day. etc. in other words fine details.
The other thing with the NX1 is, like all cameras, it gives you much better results when you light your subjects properly (even when going for the "natural" light look). The NX1, to my eye, has a huge difference in quality between lit and unlit compared to other cameras where I could compare (C100, AF100). ON your subject under the tree, if you had used a reflector or a light, you'd see big jump in quality.
Try either of the hacks first though, they're free. Try the bitrate around 160 or 180. I, along with others, haven't noticed a jump in quality above 180. You just get bigger files for your computer to choke on. The hack is reliable too, I've filmed 50 or so hours since installing without problems. If you have problem though, you might need faster SD card.