Do the Hydras and Radions have different options as far as programming? I would think the more concentrated nature of the Radion would be a little less "disco ball" effect, of course both might be equally bad in that regard.
Not sure how the G3 differs from the G4 so looking at the specs right now are all G4 spects
Looking at the LED make up of both, 23 LEDs (Radion) vs 26 (AI), but more power on the Radion than AI (5 whole watts!!!! *sarcasm*). Then it breaks down for what you as a consumer are looking for in LEDs, the AI has 6 Cool Whites vs Radions 4 but Radion has a Warm white which adds a bit more color on the non-blue end of the spectrum, AI only has 2 UV/Violet LEDs, Radion has 6, however those typically are the first to die
and they add more to that "no other LEDs on" look, the AI has 6 Royal Blue and 6 Blue LEDs and the Radion has 4 Deep Blue and 4 Blue I guess deep blue = royal blue? Perhaps other than Cree manufacturer of similar wavelength? But these royal & blue LEDs are going to have more of an impact than the violets IMO.
Now if thinking of LED arrangements is too much to think about... then don't, and pick one based on either programming or 2 vs 1 puck preference, if that's too much, buy the newest one.