Horn speakers are really bright?

Not quite (technically) horns, but the waveguides on my JBL 4349's are delightful.  I can listen for hours with no fatigue and they fill my room very well.  Took a bit to get the right amp and preamp match though.

Magnepan that's bright.

For me, sound that is homogenized with your surroundings is most important. I cannot imagine mine getting better, as a renter, than I have now: converted one-car garage  room, floating floor on Pergola ( air space) under my Klipsch (gen. 1) Forte powered by Cary Rocket 88 tube amp, controlled through a Schitt equalizer, into the new Bluesound Node. I sit slightly further away from my Fortes than they are distanced from each other… in an electronic Lazyboy, and enjoy watching TV sports (while turning off Joe Buck’s “diarrhea of the mouth”)… listening the the primo DAC in the Node stream worldradio stations from all genres, Bluetooth from my iPhone, CDs from my Sony, or HDMI ARC  off my YouTube TV.  It’s pure BLISS!

I would agree that the classic Klipsch speakers sound very different with different amplifiers. The phasing issues between drivers may contribute, as does refraction in the horn enclosures themselves in the sound I hear, and can be exacerbated by a bright solid state amp, for example. I used the Crown amp as it was grainy and not a good match. My C-J MV75A-1 would be a much better match. But I really did hear an unnatural edge to the horn systems I heard at the show.

and I really meant it when I say that Deja Vu’s horns can sound pretty great, but the cost is astronomical. 

I have Heritage IVs.  When running a Parasound SS amp and preamp they could be somewhat harsh and fatiguing.   With my Raven Nighthawk integrated tube they sound great.  Still detailed but not fatiguing.  I realize this is always subjective but I feel the tubes made a real difference with the Klipsch.