I too can't imagine JTR moving completely away from the mid-tweeter coax. That would tend to put the speakers even more in the pro or HT category than they already are and would tend to move them further away from the "audiophile" category. I'd think there would be a risk of losing some of those folks who tend to straddle those two worlds. I'm one of those folks because my system is fully a 50-50 music-HT system and I'm not so sure that I'd choose a horn over the coax to cover the mids and highs.
That is because you have yet to hear a CD/horn combo that was good enough, they do exist.
I would think the difference between them will be whether you have a treated room or a untreated room. The Directivity helps a bunch in a bright untreated room and the directivity is not needed as much in a well treated room.