I am comparing the Canon 780IS and the Sony DSC W290. Both have 1280x720 video. The Canon video size is about 3MB/s and the Sony is 1MB/s. (Canon gives you no choice for quality settings at 1280x720, Sony has normal and fine but the canon is still larger even compared to the Sony "fine" video. ) Plus, I think the Sony is actually better video, at least onmy computer.
The canon uses the H264 codec and the sony uses MPEG4 which I believe are the same thing. What explains the difference in video file size? Will there be a difference in playback on an HDTV from the camera? Can HDTVs render the MPEG4 video or will it be inferior quality because of the compression and smaller file size?