Audioquest Carbon HDMI cable

OK, well, I finally bought an Audioquest Carbon HDMI cable to put this to the test myself, i.e., whether or not there would be a difference in picture or sound quality versus a basic high speed cable. 

So, my first test was to just replace the basic HDMI cable running directly from my cable box to my TV with the Carbon.  I switched them back and forth maybe 15 times.  I just cannot tell any difference.  Now, one caveat is that the cable box will not output any higher than a 1080i resolution signal, so perhaps that could explain it.

My next test was to compare audio quality.  I replaced the basic high speed HDMI cable that goes from my Oppo BDP-83 universal player to my Denon Receiver with the Carbon HDMI cable.  In this test, it again was extremely difficult to tell any difference, but I do think there is just a slight increase in detail and definition of instruments, as well as a bit smoother sound and sense of sound stage.  Now, Audioquest touts as one of the qualities of the Carbon as "low jitter".  How important is jitter in HDMI connections?  Also, could it be that more expensive HDMI cables might be more likely to demonstrate a noticeable improvement in audio than in video performance?

Finally, I have not conducted it yet, but my final test will be to compare the two cables when playing higher resolution signals such as SACD, DVD-Audio, and Blu-ray movies that have DTS-HD Master Audio or Dolby TrueHD tracks. 

Any observations much appreciated.

I have the Audioquest Carbon HDMI Cable between an LG Blu Ray and LG HDTV. SUPERB picture quality, like film really. Of course a big advantage of the Carbon is it’s controlled for directionality as are the other Audioquest top of the line cables. I threw caution to the wind and treated all of the Carbon connector pins with the new Graphene based contact enhancer using the teeny tiny brush supplied. Whoa, Nellie!

Just changing the source and not the input cable or vice versa may not yield as big of an effect as you'd want compared to having both the input and output cables changed since you aren't going directly from video source to your tv. 
You can probably find an older Audioquest HDMI-3 used, it's likely using the same wire gauge (AQ hdmi cables aren't thick, probably 26-28 gauge) and the silver content is 6.1% to the Carbon's 5%. The only real difference I see is that the Carbon has actual carbon used to help the shielding and the hdmi-3 uses rf stoppers at each end for its' shielding help.There's actually an HDMI-3 on eBay now at $20 with no bids (though it ends in 4 hours you can ask if it will be re-listed if you don't read this in time, you can search under completed listings on eBay for ones you may have missed).In my tests the best hdmi cable that won't break the bank is the Ultralink Platinum Pro MKII, I mean it's not cheap (usually see them for around $99, luckily found mine for about a quarter of that), but it's comparable to pure silver hdmi cables that cost hundreds of dollars (similar sound and video signatures to silver). The Analysis Plus hdmi cable is also very good at $50 for 1 meter, the video is quite good (no silver in the wiring though so it's video is not quite as bright as some other premium hdmi cables that use more silver or super pure copper+some silver), but the sound quality is the real change.

In the interest of fair reporting and fair play, the 5% Silver content for Audioquest Carbon HDMI cables is for connectors only. The conductors are silver coated copper, the idea, according to Audioquest, being that most of the signal travels near the surface, so the conductors behave much like solid silver conductors. Another important distinction between Carbon HDMI cables (and other Audioquest high end HDMI cables) and other brands of high end HDMI cables is that they are controlled for directionality.