When I wired up my apartment back in 2007, a 1,000 foot spool of dual cat 6 plus coax was very expensive. So, I opted for cat5e,and then opted for heavily shielded connectors and wall keystones. While my installer hated me, he did acknowledge that when they certified the cable, its performance was actually close to the acceptable range for cat6. Now, he could just been having me on, but it did tell me that not all cable is created or terminated equally.
So to the original poster, you could of just had a bad cable all along.

As for Meridian's push to Cat7, I like to believe it's just future proofing for when Meridian Digital Media Systems start to offer other, higher bandwidth media.


Primary: MD600, MS200 (SpeakerLink to AES), Trinnov ST-2, Ayre V6-xe, Salk SS8 3x LRC.
Secondary: MC600 (whole house).
Zone one: 568.2, G57, MS200, Spatial Hologram M2SE.
Zone 2-6 (Awaiting assignment).