Since audio is not as easy to measure compared to video for subjective quality, I'd guess that audio performance is mostly determined by good shielding and careful termination quality. That is, provided that the cable is of sufficient construction quality to perform flawlessly in any video tests one might perform...
Anyhow to answer the question... The picture would have look good with any properly constructed HDMI cable.. As in anything in life there are those (rare) cables that are improperly constructed... Same with the sound