Once you hear a good JBL system, it will match anything. Plane and simple.
No I'm not currently using horn, but it doesn't mean I wouldn't. Me it's a room size issue. Horns need room. Great horns cost money, to buy and run. A cheap amp, source material or source player will stand out like a sore thumb.. JBL Everest will show every single flaw in equipment, or sound like heaven with a large enough room, acoustics and great gear..
Everest series are wonderful speakers. BIG footprint too... They don't fall over in earthquakes either.. :-)
Regards