there won’t be any difference, but I do find it kinda funny that you went from a power supply change to assuming cables will also provide a benefit because the psu did. you know that makes no sense right?

passive crossovers do not have break in

It sounds like you’re just annoyed that the increase in consumer knowledge has led to many losing interest in the majority of brands out there, which is fine because that info mentioned above has shown us that A LOT of gear is junk.

I haven’t heard any older brands like you’ve mentioned sound anywhere near as good as more modern designs that aim for better neutrality on axis and employ techniques to get off axis response these older brands could only dream of.

I do think REL is overpriced, doesn’t have anything to do with what people here say, but more based on my understanding of speaker design. I don’t see any DSP in their subs which really puts it off my list of ever considering, and their is some data out there to show they don’t quite keep up with some cheaper options out there. For the cost you should really be getting DSP, which is damn near essential for actual good bass, I don’t mean “this sounds good to me” I mean actual flat low end without peaks and nulls. I also have a problem with how REL just uses audiophool BS to market their subs, like “fast drivers” and their suggestion of sub stacking seems to show they don’t really understand low frequency reproduction in rooms. It works though, because most people don’t know jack about room acoustics. See below.

don’t even need two like the majority of the home theater sub will tell you, at least not in a living room the size of mine.

This sub rightfully suggests multiple subs not for output, but because multisub is one of the best ways to get good bass response in a room. By placing subs around room the in strategic positions you can excite room modes more evenly leading to a much more even response with much better coverage in the room. REL’s stacking doesn’t work the same at all and it really is just a waste of output.