Horn speakers are really bright?

I don't find most horn systems to be "bright" (pronounced top end response), but, many do have a peak in the upper midrange that some might consider "bright" in sound.  The very best horns don't have that kind of peak, but, few have heard the best compression drivers on the appropriate horn (e.g., Western Electric, IPC, G.I.P., YL, Raycon drivers and horns).

Another issue is the appropriate amplifier.  Horn drivers are extremely detailed and revealing of different amplifiers being used.  It is very important to find the right amplifier match (typically low and medium powered tube amps).  The wrong amp can sound thin or harsh and "artificial."  While I am not a Klipsch fan, I think the classic speaker line is quite decent sounding when they are coupled to the right amplifiers; most often they are heard at dealers being run with crappy electronics so I can see why there are a lot of people who do not like the sound of horn systems.

Jallan,

I agree that the Deja Vu custom builds are fantastic, albeit expensive.  But, some of the builds are much less expensive than what has been brought to Capital Audiofest  and they deliver much of the same sound as those you have heard.  In any case, those builds do demonstrate that sharp and unpleasant peaks are NOT INHERENT to horn/compression driver speakers. 

Even the Klipsch speakers that a lot of people have heard and don't like can be made to sound quite decent with the right setup and associated gear; I've yet to see a commercial setting where the proper electronics were used.  

The strength of a top notch horn system is the ability to sound great at very low volume levels--they still manage to sound lively, detailed and engaging even when played softly.  Some systems do tend toward "shouting" at extremely high volume levels, but, I hardly care about that because I don't like to listen at that kind of level.  Moreover, the very best amps, to me, are all low in power and can deliver great sound without having to "raise the roof."  I don't care if a system is unable to achieve rock concert listening levels; if my system ever sounded as bad a rock concert, it would be gone the next day.

It is detail, dynamics and an engaging sound at low volume that is the hallmark of good horn-based systems.  Just because they tend to be big in size does not mean they have to be played loud.  The ability to play softy is why these giant systems are more commonly found in tiny Japanese apartments than is the case here.  

I tend to measure how good is a particular component not by how it sounds when the volume is up, but how it sounds at low volume--the lower you can go and still get satisfying sound, the better the component.