Ok, that slash and maul article has been beat to death on the forums. I have responded to its content, and will again as it is an affront to how seriously we take our designs and the truth.
In 2005 I declined Mr. 10's offer of a "review" in exchange for us loaning him products. His response to my decline was one of someone being seriously affronted. He said with emphasis that he would get the product some other way and review it without our cooperation or permission. It doesn't take more than a cursory read by a 5th grader to see the effect my decline had on the tone and content of his comments. BTW, this happens a lot. Everyone with a blog thinks they are entitled to loaned products and act shocked when we decline.
He "reviewed" a product that was a long out of spec product by 2005, so it is no surprise that his "photo's" didn't match what we were producing then much less now, or the listed spec's on our web at that time. I wish once in a while people would question "pop-up" review info just for a moment, and not simply accept web-made-up negative information as accurate without looking a bit further. This fellow plowed ahead with half truths and made up garbage without question because we failed to accommodate him-- it was that simple.
There have been many advances within our products since the pictured H4 was made in 2002 and an entire board constructed with the multi-element filter array that is both pictured and described in detail on our web. That network did not exist within the first production run model that 10 procured and wrote about in '05. Our listed specs and tech have been _exactly_ accurate on our web related to current production every step of the way.
Now, to answer the QUESTION, the Hydra models all have dedicated filter network boards mounted and wired to the back of each duplex. Guardian models have only a single multi-element filter board per unit. In complex systems that use a single dedicated line and multiple components, the Hydras have a clear advantage as each duplex is more isolated from one-another internally. In more simple systems, or systems with multiple dedicated lines that have separate line/s for amps, the Guardians are amazingly close to the Hydras in performance.
I can answer your questions in more detail if you contact us directly. You are likely also to avoid the pot-shotting and half truths that appear from either the whimsy or agendas of others.