Just because a video uses an MP4 file wrapper doesn't mean it isn't high definition. In fact, the MP4 modes in the Canon models (e.g., the M52) are all high definition. Nor does MP4 necessarily mean a drop in image quality. That's usually the case, because most camcorders that offer it reduce the frame rate (e.g., to 30fps) and/or reduce the bitrate (e.g., to 4 or 9 Mbps). But not every camcorder does that. Samsung's models, for example, have used an MP4 wrapper for years for all of their recording options, including the highest bit rates they offer on a given camcorder.