I discovered this thread quite a bit after it was relevant, but thought I’d add my comments in case anyone else is considered this product line.
I became an AQ dealer specifically because I thought Niagara seemed to represent an advance in power conditioning. The 5000 wasn’t available at the time so the 7000 was what I brought into the listening room to power both a 2 channel and more modest home theater system.
Being in NYC we may have more power problems than those in suburban areas, but the 7000 brought significant benefits to our demo system, with mono block BHK 300’s plugged in.
Dynamics actually improved since more current is available for short bursts, which is not something one typically thinks of a power conditioner doing.
The TAD CR1’S speakers we use are highly revealing, and the Niagara 7000 has Added low level detail and naturalness to the presentation. It also removed a bit of a ragged quality.
What I was not prepared for was the improvement to separate home theater system, which is no where at the level of the 2 channel system. All of a sudden I was hearing a much more refined system, smoother with strings that seem to hang in mid air, reminding me of a high end 2 channel system and not HT.
While I’ve not heard the 1000 or 5000 I can attest that the 7000 took both systems (plugged in at the same time and isolated from each other) to another level of musical refinement and dynamics.
Another great aspect is that only 1 AC line is needed.
Luckily I get to hear live unamplified music from up close often, so my reference is live music and not other audio systems.