That's all marketing plain and simple. Sure, if you spec cables like that you may see a theoretical signal improvement but will you hear it? No. Certified high speed HDMI cables from a reputable mfr like Monoprice, MediaBridge, etc will give you all the audio/video quality you will ever need. For runs longer than 25', you can use an active cable like Redmere or, if they are to be installed in-wall, CAT-6 + HDBT. Companies like Monster and Audioquest make tons of money on their cables with slick marketing and fancy specs. The specs are probably accurate but in real world settings, i.e. your viewing/listening environment, they are pretty much useless.