A bit late post but I bought radion G4 and hydra 52 hd to test side by side. Radions were amazing other than that disco ball effect I was able to reduce with lowering surface agitatation. Hydras have almost none of that no matter how bad agitation is. In my eyes hydras look more balanced as far as whites and blues than radion. Also all radions I always see pics or video always have a purple tint to them which was weird haha. I ended up selling radions but wondering if I made right dessision. I love surface agitation from my gyre but radions hated it.