I have a Coralife 29, and did a RapidLED retrofit kit back in March. I love it, with three caveats:
I'm probably a bit above the average of electrical and electronic skill level in the hobby. The Rapid kit as delivered to me came with complete, but not particularly detailed instructions. I could easily see someone with less electronics experience popping emitters during assembly and testing. I was also unhappy with the electrical installation as provided, and added quick disconnects (as supplied and instructed, the hood becomes hard-wired to the ballasts,) and quite a bit of modification of the electrical system, for mechanical strength.
My array has the recommended 10x Royal Blue, 8x Cool White, 4x UV, and one each red and green emitters, and I still I wish I had gone bluer, in terms of color balance. I end up with the white array turned all the way down, and the blue/color/UV array turned all the way up. I'd like the ability to go just a bit bluer. This is a personal thing, and Rapid will send whatever emitters you ask for, but you're pretty locked-in once you actually assemble the thing. (Yes, I could change them, but it'd be a pain in the ***.)
Heat. Holy crap heat. This is south Florida, and with a 78°F room temperature, and stock PCs, my tank would hover around 80-82°F with the lights on, and both the equipment lid and feeding lid open. After the LED installation, that temperature became scary-high, which led me to a chiller. Not cheap. Of course, the chiller has also made my tank significantly more stable, and consequently healthier, and cut WAY back on the amount of top-off water I use. Not a dollar saver, but its significantly more convenient now that I'm not schlepping five gallons of RO/DI around my living room every week.
TL;DR: This array is more than enough light to grow anything I could possibly want, and I'm very happy with it, but I would suggest something open-topped if you're unable or unwilling to run a chiller.
Here's my thread in the vendor forums after I finished it. I hadn't completely figured out the controller, so the colors were still rather white.
http://www.reefcentral.com/forums/showthread.php?t=2395030
And here's a current shot. It shows up quite a bit bluer than it appears to the eye.
http://i.imgur.com/IMdPCyr.jpg
If you have any specific questions, shoot.