The biggest issue is when the shorter wavelengths propagate within the horn. They can cause some cancellation effects leaving holes in the response.
That all part of the "secret sauce". I say secret, but its patented, so you can look it up and learn for yourself. Its beyond clever in terms of acoustic crossover engineering. That said, I am not a fanboy, there are plenty of good speaker designs, but in my HT, I needed the narrow directivity (which takes some getting used to) and they work beautifully in that. Fans of Omni or OB speakers probably would find them too headphone like, it depends on that overall setup. I have never liked omni speakers I've heard, some OBs are good depending on setup again.
