I'd say too directional with only two points of light. You could get two and see how it goes, planning to add another 2 if/when necessary. You might also find you miss your t5s and ultimately run a hybrid system with Radions and t5s. I run Radions and t5s and really like the combination (control of the Radions for sunrise and sunset and changing color temps and t5s to even out the lighting and eliminate shadowing).
It depends a lot on what you're trying to keep. If you're doing LPS and SPS like montis, bird's nest and other relatively easy SPS, you might never need more than a couple of Radions. Acros are likely a different story. Changing from Radions only to a hybrid system dramatically increased my success rate with acros.
I would try to hang the Radions as high as possible and try to get your hands on a par meter to check your lighting intensity. Your eye (or at least my eye) is a very poor judge of intensity. With Radions only, areas of my tank that appeared to have similar lighting levels had dramatically different intensities.
Finally, I would consider getting the new Radion diffusers. I just started using them myself so I can't comment on the 'results' from using them but, they seem promising to reduce hot spots directly under the pucks and blending colors better, particularly if your lights are only going to be 8-10 inches above the tank.
Matt