It sounds more like an indication of lack of synergy between your chosen pieces of equipment, to me.
Please excuse me if that's been said multiple times already ... I haven't read thru the entire thread yet, I'm sleepy and want to crash and was excited that there was something I could respond to, ha ha ha..
I guess when you actually have it in your system, you can appreciate how important it is for the bigger effect? Something like that.
The imaging and sound staging I get from two different pairs of completely different types of speakers, meaning one's a legacy model big44" tall electrostatic panel with an attached subwoofer and the other set is a pair of bookshelf speakers on some good stands. Albeit, they're a bookshelf that performs exceptionally well, especially given their price tag. Usher Be 718 is the model. I got them nearly brand new for twelve hundred including delivery and got damn good stands for not too much.
Both of them perform unbelievably well. This sounds so cheesy, but a lot of you guys would probably say the same thin: I'm so! in love with the sound I get out of both pairs.
If I can do it, anyone of you can because I haven't come close to spending what a lot of these guys have. Probably considerably more than others, I dunno.
I'm familiar with that fatiguing sound you're talking about. Good news is, it can get better. I'm not the one to tell you ... but I've listened to the seasoned regular members around here and headed their advice.
The thing that would probably make the biggest noticeable difference is a good power conditioner. I. personally, am into PS Audio's Power Regenerators. I have a PS 15 and I believe the older used PS 300 would have a very similar effect.