Nordost QKORE

But how does this "passive approach to obtaining an artificial, “clean” earth for hifi audio systems" compare with Puritan's ground master, where one does actually connect the ground of the power conditioner to a ground rod on the outside of ones house to earth? 

I don't know, I have the latter, I am not implying it is better, because I don't know. I would hope not as it is quite a bit less money. I imagine the ones who have tried both in their system is slim to none. 

I also imagine employing both grounding strategies may be counterproductive? 

This Nordost is similar to synergistic research's grounding blocks with the exception that the SR is active- it plugs in- anyone compared these? 

Running another separate ground rod to earth is against code in most places so watch that. It is here in Australia, where having different ground rods can effect the MEMS connection at the fuse box.

Probably best comparison would be to compare Puritan Groundmaster City vs QKore 1 on a power distributors ground terminal. There is a large price difference, the Puritan is only $250.

I just upgraded my QKore ground wire from standard to premium for one of the connections, a BNC digital input on a Naim streamer.

From first plug in, it seemed a subtle and just OK upgrade, like better bass. But after leaving it working 48 hours, a new level of transparency and lower noise floor that was surprising. A great upgrade for the price, the 2m Premium QKore wire being only about $500 USD. One of the cheapest cable line upgrades Nordost do...

I was using a RCA-BNC adaptor on the standard QKore wire, so don't know what difference that could have made.