newtoncr,
I like your approach of narrowing candidates to a few that you can realistically audition. As it is turning out, you are looking at single driver or single driver used as wideband driver in a multi-way system, rather than traditional "horn" systems (compression midrange driver). Personally, I've not heard many single driver systems that I would consider completely successful (Charney and Voxativ being the exception). I really do like systems where a driver intended to be used as a single driver is used as a wide band driver in multi-way systems. I've heard drivers that I thought were very rough and peaky sounding become remarkably well behaved when used in two and three way systems.
I have heard a couple of different Horning systems and I do like their implementation of single drivers in multi-way systems. Their speakers are very lively and vivid sounding. I find them a touch bright, and a bit ragged and sibilant, but, this is a matter of taste, and overall, I do like them. I cannot recall the electronics used in the demonstration, but, it may have been Tron one time and Thoress another time. A friend has Tron electronics that I think are quite nice sounding.