Go Cat8!

I am certainly not an expert on Cat6 vs. Cat8 cables, but I'm fairly certain that unless your entire network is at the Cat8 level (highly unlikely) the only explanation for a Cat8 cable performing better is that your Cat6 cable wasn't doing it's job.

I don't think there's even an official specification to define CAT8 and maybe not even CAT7.  

I am reporting on what I hear: replacing cables between Etherregen and server had a major impact.

May I ask what led you to choosing the Onti Cat8 cable as an upgrade to your previous Maicord Opal Cat6 cable?

It appears that a Cat8 cable uses a lot more shielding compared to the others and is expected to be quite rigid.  From what I've read on the Blue Jeans Cable website the terminations are key to ethernet cables and the reason most cables do not meet the advertised specification.  I have several of their Cat6 cables and they come with a test sheet for each cable to certify that it meets the specification.  I reached out to them today out of curiosity and they said that there isn't a patch cable certification for Cat8 so there's really no way for a manufacture to ensure that it's compliant.

For what it's worth, I'm not totally against the concept that cables can make a difference.  In my limited experience I've heard clear differences with power cords and analog interconnects, but didn't hear anything with an upgraded digital interconnect.  I just know that ethernet cables are just part of an overall system where an individual patch cable can become a weak link if poorly constructed, but no individual component can elevate the capability of the system.