I like the AI Prime, it says it's rated for 24x24 but I'm not sure what it will be like toward the ends of the tank. I like the simplicity and iPhone app. I'd LIKE to eventually bolt a small t5 fixture onto it depending on coral growth since, IME, t5 worked very well for growth in both sps and softies.
The AI Prime is cheap, clean looking and from what I can tell from the internet... reliable.