Just remember - not all 720p files are created equal 
For example - Heroes 720p is circa 1.1Gb per episode. I've got a film at home which is also 720p, which is 8GB. Biiiig difference in bitrate- Heroes plays perfectly over homeplug, above certain bitrates (trying to work out what bitrate just now) the HomePlug 85 struggles (for me at least, and that's a new house with good wiring).

For example - Heroes 720p is circa 1.1Gb per episode. I've got a film at home which is also 720p, which is 8GB. Biiiig difference in bitrate- Heroes plays perfectly over homeplug, above certain bitrates (trying to work out what bitrate just now) the HomePlug 85 struggles (for me at least, and that's a new house with good wiring).