Couldn't you say the same the other way? Its just that "your stuff" is the program and "my stuff" is my computer?
No, because I don't work for JRiver. I have no skin in this game. I'm just telling you what I've found based on extensive experience.
I think the issue that most of us don't see UI interruptions when audio analysis or thumbnail building are going on. I certainly don't, even when adding or analyzing large numbers of files.
Nor do I. Performance is impacted slightly, of course, if I'm analyzing a bunch of files, but not to the point where I'd call it frozen or sluggish
at all. I
regularly use MC for other tasks while analyzing and importing huge sets of files.
Audio analysis during import
can certainly impact responsiveness, depending on your particular setup. It is designed to be low process priority, but not to an extreme (otherwise it would take forever). It is a balance between using resources, and completing quickly (otherwise, the impact is just stretched out and bothers you for
longer). Hendrik (who does work on the code) explained this above.
The biggest single factors are CPU, disk throughput, and RAM. A lot also depends on the Views you've structured in your Library. I don't have enough information about your setup to diagnose the cause, but a pretty decent wild guess would be that you're mostly limited by disk throughput because your storage medium for your files is on a slow NAS, and you haven't disabled the option described in the guide that checks for file availability. Or maybe you've moved the thumbnail cache storage off to a slow disk? Everything you've described sounds like a storage bottleneck.
Your media storage might also be just too slow to use for audio analysis during import without impacting responsiveness. If this is the case, you can either turn it off, or change your staging area to a faster disk so that the analysis and initial import happens on a fast disk, and then you move the files to the very slow storage afterwards.
But there are a wide variety of possible causes. I'm guessing in the dark.