I'm beginning to source parts/fixtures for a 135 setup, and have decided to go LED. I've had a DIY LED array over my 12g Nanocube for about a year now, and love the color, shimmer, and lack of heat it produces. It's only 11 3w LED's, but it is MUCH brighter than the 150w viper hqi it replaced. I am getting good growth from my sps, although some of them a re mad b/c they get too much light.
I had been thinking of going the DIY route, but I've heard good things about Aquaillumination fixtures, so I ordered one as a test unit. It arrived a few days ago, and I played around with it quite a bit. The cree XPG's are markedly brighter than my XR-E's, and this thing is BRIGHT! The sunrise and sunset can be programmed for up to an hour with the standard controller, and intensity of each color controlled independently. The cooling fan is almost silent as well. Just ordered 2 more units and a 6 foot rail system. I will need to pick up at least 2 more when funds permit, but this tank is still at least 6 months off. I figure that these fixtures make sense for a number of reasons: 1) no bulb replacement, 2) color, shimmer, and brightness equal to or greater than MH, 3) less electric usage, 4) no heat = no chiller = even less electricity use, 5) dimability, natural sunrise, sunset, 6) no additional external moonlights required - moonlighting done by controller, 7) possibility to add more functionality with external controller later, 8) expandability.
I too looked at the ecoxotic fixtures. In the end, I decided against them mainly because they use 1w LED's and I don't know if they'll penetrate the 28-30" I'm looking for. I know 3w LED's will though. Just something to think about.