I presume the differences are down to better quality cable and it's sheilding, i know that this is something HDMI 1.3 is based upon and a must for that version.
Better quality cable and sheilding might reduce errors, but it cannot make the picture "sharper" or "better".
Without some proof, you cannot uniquivically say as you did "it does", only that it does "in your opinion".
However, I am happy for someone to correct me if I am wrong, and have asked several times in this forum for people to put forward an explanation as to why an HDMI cable might degrade the PQ in normal circumstances (a cable can never improve PQ). I know why a cable might introduce HDMI errors, but such errors do not affect picture sharpness or overall PQ.
So far, no one has done so, including those who sell the things.