I have them over my 40b right now. I have the 36"-48" ones too so I have perfect coverage and the highest amount of light I can get. What size tank are you wanting to put these over? I am keeping softies and some LPS so far, but its only been like a week or two. I am not coming home for a few more days, been gone all week so not sure if the corals are still liking them, they seemed to like them alot before Ieft.
I think I might be lucky since my tank is not very deep, any deeper of a tank and I dont think it would keep much at all.
The chines fixtures will grow anything and as long as they are adjustable then I'd opt for those. I am running 5 of them and thy work very well, actually very very bright so be sure to acclimate corals with them.
I bought the orbit cause of the slim design and nifty features and timer. They work great btw, but how often do you think you'll use the storm effects? lol I only use them to show people how cool it is other than that it serves no real purpose.
The remote iss handy and the programming is pretty easy, now if it will just grow corals lol