I've been trying out a whole bunch of HDMI cables lately for a dedicated headphone setup I am assembling. Using a Denafrips Gaia I2S out to a Denafrips Terminator 2. So far my results have been very mixed.
Tried several more affordable options from Pangea, Kimber, Analysis Plus, didn't care for them.
Tried what I call mid priced cables from Wireworld and Cardas, didn't like them either.
Tried some more expensive models from Wireworld and Audioquest, not really great or even a big improvement over the others.
I was starting to question whether the Gaia was worth using, and thinking maybe I should just go USB from transport to DAC. Then I hit on the DH Labs HDMI which is excellent. Eventually I found that I also really like the Voodoo Cable Silverstream, and both the Vodka and Thunderbird from Audioquest.
I'm still experimenting, so far my conclusion is that HDMI I2S cables really matter and some are much better than others, also that price isn't always the main factor.