I have the hagen single 48" fixture and it's not all that bad. I can't imagine what was going through their minds when they were coming up with the mounting system, but other than that the light comes on when I need it and it goes off when I want it to. Which is all a light is needed for.
and it seems like the catalina is the best option for sure, especially from what ive heard of their customer service. I actually have a 48" 4 bulb t5HO tek light fixture that im not even using its a shame