yes the ATI's are beasts when it comes to T5. I have a PM 36". And recently saw TWO 36" NEP's on a 72" tank. I think that the two combined were still less light than my one ATI PM. I wouldn't use the NEP for a sps dominant tank...but a mixed reef should be ok. Just be sure to get better bulbs that what come standard with it. said:Very true. I have a NEP on my 30gal tank and I immediately switched out the bulbs for ATI and UVL bulbs. I've got a couple of SPS in the tank and they do OK but their growth is nothing like it was when they were under halides.
My only complaint with the ATI fixtures is they don't offer mounting legs. I don't have the option of hanging from the ceiling so it makes it harder for me to use one. I'm probably going to switch from halides on my 75gal to a TEK Elite 6bulb fixture.