Since I (well actually all of us) get isolation for free by using the ethernet sockets on my Meridian gear/everything else I'd love to hear how the GISO filters out the high frequencies without affecting the high/very high frequency data?

Since you've got about 31 ish MHz from your data (assuming 100Mbps) what is there that's going to be higher than that to filter out at a level that would be a problem?

Shouldn't be much from switch mode up that high that shouldn't have already been taken care of by design and you'd need to allow more for Gigabit to work anyway.

Fairly sure MLT-3 isn't meant to look like gentle hills and valleys.

Has there been any proper blind testing performed yet? (And that also checks that using a short length of UTP to break the ground loop if STP is being used doesn't give similar results?)

Matt