I have in my inventory Radian tops, subs and monitors (the old microwedges). I think they're great. Great volume, clear even sound, robust and reliable.
The NEO driver you're asking about is relatively new, and I have not heard it specifically, but Radian got it's start making diaphragms and compression drivers for other companies so they take their components seriously and that is their new HF flagship.
Having said all that, one of the appeals about the Radian products is their very well thought out coaxials. I find them very plesant to talk to directly if you have product questions and US Speaker seems willing to talk about the products they sell pretty candidly if you want comparisons to other companies mega drivers.