Yeah, it’s def true though. My iPhone also does 720p HD but nowhere near the quality of a DSLR that shoots HD. It’s all about the size of the sensor and the LENS attached. Audio quality isn’t bad on most of these cameras (even the iPhone) but an external mic is recommended for the DSLR’s.
Like so: http://www.dslrnewsshooter.com/2009/09/25/another-night-in-beijing-production-canon-eos7d-movie/