This is not complicated. Your right on the mark, Last Lemming. The recording has nothing to do with it. We're talking about gear. However, noise floor is not the only factor influencing low level resolution. Typically, if you put your ear up to the speaker at 0-half volume and don't hear anything except the tweeter, the amp has a low noise floor. Especially on an efficient speaker like a Klipsh. If it's noisy, it stands to reason that resolution is going to suffer commensurate with the level of that noise since the amp is going to amplify whatever it's being fed. At "couch" distance it's irrelevant unless of course you can hear it there! Differences are apparent when A/B ing amps with the same recordings and other gear. So in answer to your question; yes, they mean the equipment is quieter. From your description it looks like you have a nice quiet amp.
Blackness - how quiet does it need to be?
In almost all gear of any substantial value the concept of the blackness, quietness or low noise floor comes up. A reviewer might say that the noise floor was noticably lower when reviewing a particular piece compared to another. Now I get that low noise translates roughly to being able to hear more music and nuanced detail. Thing is, when I turn on my system and no music is going through it, I can't hear anything, unless I put my ear right up to the speaker and the AC isn't running and the fan isn't on, etc. And with music on the only thing I hear is any recorded hiss that might be from the recording. So what I dont get is when they say a piece of equipment sounds quieter, do they mean somehow that the hiss on the recording is lower? I cant see how that would be possible, or are they talking about the hiss of the equipment without muisc? In which case I cant hear it at all when sitting down on my couch. I don't have the world best gear, so I'm thinking are they overplaying the "quiet" card.