HDMI is a digital signal, you either get perfect, or nothing, the only time cable quality comes into play is with particularly long distances, or weak sources.
the bad picture yall are getting is probably due to the video source, streaming video... streaming video, even at HD resolutions is compressed, on a big screen artifacts from this streaming becomes much more noticible.
try downloading a high quality HD 1080 resolution AVI video, copy it to your bionic, and then play it through the HDMI cable, I bet it will look much better.