Has anyone made the jump to $uper High end and were disappointed?

I've owned my pair of Quad ESLs since 1973. They were eventually put to the side (and eventually into crates) while I used the Crosby modified 63, which was, overall, a better performing speaker in terms of bass, dynamics and dispersion, but they lacked the utter coherence of the original in my estimation. I only recently got my original pair restored by Kent McCollum, and they sound wonderful, with a pair of old Quad II amps, restored and re-glassed with GEC KT 66s. I don't have fancy wire, and in fact, have still not finished the turntable, so am using a CD player as a source-not a particularly notable one. The Quad based system is a joy to listen to.
But, there are many other things I own that I also like:
-my Lamm ML2s are wonderful with horns. I will probably not part with them.
-my Kuzma XL and Airline arm is now in its 11th year of service and I'll still thrilled with its performance. I did have to buy a pricey isolation platform for its new location, but it was worth it.
There are a number of other components I have owned over the years that I regard as enduring and bring me joy.
The point of diminishing returns is a very personal one and cannot be measured by any objective criteria in my estimation. Now that I'm past my big earning years, I'm more sensitive to value for the dollar but never felt compelled to upgrade for the sake of the latest and greatest. 
I'm finally looking at digital sources, to give me more access to music, despite my life long commitment to the LP.  
For the last number of years, most of my money relating to hi-fi has gone into records, not gear. I'm also enjoying it more than ever. 

@jji666 - fair point, and the conventional wisdom is that speakers and audio systems in general should be genre agnostic...
The presentation will be enhanced by a better system in my estimation. I use horns in my main system and though those aren’t necessarily more expensive than dynamic speakers, they do a marvelous job in dynamic swings- (the so-called "jump" factor). I play rock on my vintage Quad ESLs too, and they give a different perspective without the dynamics, sheer volume or scale (though as a smaller portrait in miniature they can sound fabulous with well recorded rock).
We attended the King Crimson show in Austin a few nights ago, and it was fun to take in the latest live recording on LP- the Toronto 2016 recordings for a morning after "hair of the dog." No way could I reproduce the sheer volume and sock of all three drum kits and the depth of some of the synth and bass guitar sounds with all of the power of a 2900 seat auditorium in my comparatively smaller listening room, but it sounded pretty good. (It’s a good live recording too).
All the criteria used to differentiate sound quality applies, at least to my ears- yes, I use real instruments as a reference and want to evaluate a system hearing a grand piano-- often a very difficult instrument to record and reproduce faithfully--but much of what I listen to--early post psych/pre-prog folk and hard rock sounds wonderful on system capable of high quality reproduction.
The fault often isn’t even the amplified v. acoustic instruments; to me, the shortcomings in a lot of popular music have to do with the quality of the recording. The era I’m fond of-- late ’60s, very early ’70s- was typically fewer tracks, often less outboard processing and in many cases, less overdubbing. (Not to say that the studio concoctions in the ’70s sound bad when the engineer because auteur rather than just recordist, but the risk is greater when the studio wizardry falls flat). The bands also didn’t have the crutch of being able to punch in a better take- they could and often did play through the whole song in a take and that can sound better than some Franken-recording sewn together from parts. You can hear the room, the position of the instruments and get a better sense of the stage if recorded that way (and not manipulated to hell and back in mixing and other post-production "magic.")
And, without the ability to do 100 takes and stitch together a "perfect" recording from multiple takes and overdubs, the natural acoustic, such that it is, along with bleed through, gives a coherence to the sound that is equally telling.
The other reality for me is that I’m not listening to audiophile recordings. Some just aren’t great sounding. And there, no matter how good or bad the system, it isn’t going to WOW you with sonics- the goosebumps come from the composition and performance.
The question -- I guess it should be rhetorical-- is how much one limits their listening by the sonic quality of the recordings. I can’t live on a diet of audiophile warhorses, and like all kinds of stuff, from pop to proto-metal to hard psych as well as some of the more adventurous material that defies genre.