I'm running the Hydra 26HD on my Reefer 170 with great success. Noticing almost daily growth on my Acropora. I just did a par check last night and realized my Acropora aren't receiving that much light so I'm surprised about the growth and color. I just amped up my intensity today and set up the acclimation mode.
I had connection issues at my old house with the original ones I had. But that was because my router was awful. I've had. I issues at all with the new one I'm running.
Planning my current upgrade for my new house in the next few months. I plan on doing HydraHD/T5 combo again probably. That being said though, I've always had great success with these lights. Only issues with corals were complete user issues (changing settings too much, blasting them on accident). But after I got them dialed in, they were great.
I'd recommend them over and over again. But that being said, I would hesitate trying the G4 Radion or going back to ATI T5's if I had a much more mature SPS tank