Radion Pro is a fine fixture. You can put them over a tank and see your corals almost respond immediately. They look good too.
I would not buy another AI fixture either. Something about their LED choices or their frosted lenses, just did not work at all for my corals.
The Mitras is on par with the Radion in some ways, but I still have to give the Radion the nod.
Kessil A360W is what I use and my growth and corals have done fantastic. Everything from SPS, LPS, to clams have done great.
I say again, it is the only true UV output light (LED) on the market. And yes, UV and the UV spectrum of LED's are a must in any fixture.
Go with the Kessil, I do agree you should go see them in person to make sure you like the unique shimmer look. I can't imagine anyone that wouldn't, but that is just my opinion.