I done horns, planners and dynamic speakers - some a couple of times. It was fun, painful and rewarding. Each time I settled on a speaker type I had changed out other components to better match that speaker type. So figure that in too, because it will happen. Now i got off that merry-go-round and picked dynamics, third time, for better all around performance (IMHO). You may decide something else. My only advice is get the dealer support you deserve. Insist on it.
How many responses on these thread where from dealers? Bet there are a few and that's good. Why not sept up to providing a home demo, free or not, of some of these expensive horns? This might be difficult to arrange, but once you narrowed down your preferred horns to three. Find dealers that will do that home demo.