Really, the test results and listening impressions are exactly what I would have expected for this speaker. You can't beat physics, and the pros and cons found match what I would imagine would have been the understood issues going into the design.
The drivers used are without doubt seriously expensive. JBL have the advantage of in-house manufacture of drivers. They can amortise development costs across a lot of lines, and make custom changes for a specific product. But $7.5k for these speakers is hardly a surprise.
What is interesting is a two way design with large waveguide. Again, the pros and cons are well known, and the result is exactly what you would expect. The speaker struggles at the crossover point, where neither driver is really happy. But you do get fabulous directivity in the top end.
Why a two way? Why not a three way? Well they make one, the 4429 is exactly what you would expect. Basically the same speaker in a 3 way. But they end up compromising on the waveguide, and whilst they proudly trumpet the angles for the 4349, they are mute on the angles for the 4429.
The power handling, and dynamics of this speaker will be near impossible to match with a different approach. This speaker will be delivering clear undistorted sound when the Salon 2 drivers are molten puddles. Whether you need or want that ability is a different matter. But for some the trade-off is clearly in favour of the JBLs. Harmon have it both ways, since they own both brands.
A collegue of mine is a seriously high level jazz sax player (of international standing) and it is interesting that his home sound system is basically down this path. Not exactly the same speakers, but of the same ilk. He very much favours the dynamics of live sound and performance over the more smooth sound of a more HiFi approach. It is not possible to say he is wrong, but it is possible to have a different preference.