I may as well add my 2 cents in here as well.
I bought the Axi2050's and some 402's at the end of 2019 and have done extensive testing / listening.
The short version is that my subjective opinion is somewhat in between Chris A. and Bjorn's.
Even with EQ to flatten and extend the HF response of the Axi2050's I would rate the treble as good but not exceptional. Not bad by any means but certainly not the best I've ever experienced. The Axi2050's engineering do get it to the upper treble octave... sort of...But make no mistake it takes a LARGE dollop of EQ to get there. With that said, what I do find exceptional is the midrange and lower treble quality. My hearing isn't what it used to be and attenuates fast beyond 15kHz these days. I can still hear 16kHz with test tones but it takes appreciable level. With that said, I put much more weight on the midband performance over the upper treble, so for me the tradeoff is worthwhile. Take that FWIW. YMMV, etc...
I originally intended to buy the Radian 950Be drivers but at the time these were much cheaper and the new thing so I went with the Celestion's. Curiosity about those may eventually get the best of me.
These drivers are rugged and do seem to give more useful low end extension than most other 2" format cd's. It may be a bit over hyped depending on what you read and the application. For domestic use, where it'll never see more than a couple volts on peaks, it can run very low without any risk. For large format / HO use I'd not cross it lower than 500Hz. For my situation and type of use, which is somewhere smack in between light domestic use and heavy duty reinforcement, I wouldn't run it lower than 350-400Hz on the 402 to keep diaphragm excursion and THD in check.