I have recorded plane during the pattern with ceel phones, digital cameras that have "Video" function, a cheap $70 3.1 MP Aiptek digital video cam that uses Compact Flash cards for memory, and a mid- high end digital hard drive video camera. Cell phone and still camera with video function are low quality and if you back up far enough to get the whole circle there is not enough detail to spot errors. Picture tends to pixilate and moving image gets blurry.
Cheap video cam is O.K.- but same issue with getting far enough back to capture the entire maneuver. It has more detail and you can easily see bottoms / corners, but little wiggles and bumps are harder to pick up. Still a bit blurry due to fixed focus lens.
The Panasonic HDR has a real zoom lens so you can get back far enough and still have a clear image, the frame rate is higher and the motion is crisp and detailed. Down side is they start around $300+.
It's the same as any other tool / device, better quality + more money. If you are going to buy someting I would tend to go the video camera route.