As you can see the stabilizer crops the image a little bit, so you loose some resolution and sharpness. Basically the more stable the original shot is, the less it will be cropped during stabilization. I consider the stabilizer to be used more for bumps and jitters rather than substantial, jerky movements.
Overall I am very impressed with the camera. I used to own the XH A1, so this is a familiar experience. Although, quite refined, especially in the ergonomics and placement of buttons. Canon is very good at finding the happy medium between too many buttons and too few. And the variety in the shape and feel of each button helps to distinguish them without having to look at them. Of course, the greatest thing about this camera is the beautiful 30-530mm 1.6-2.8 L series lens. I originally owned this lens on the XH A1 when I was 15....I had no idea what I was doing...nor did I understand the quality of lens I was shooting with. This lens is absolutely incredible.
One of my complaints is that Canon went overboard with the custom picture profiles, as they did with the XH A1. I'm not kidding, there is a setting in this camera that allows you to adjust the saturation of the shadow areas that are effected by sharpening of the color red. You can have set the level of sharpness in the shadows, mid-tones, and highlights, and then adjust the RGB matrices in each of those areas. It's crazy. I suppose they did this ensure that their camera goes on the BBC broadcast certified list, which it did. But seriously....I will never use most of those settings.