My build thread is here if you want to check it out:
http://www.canreef.com/vbulletin/showthread.php?t=62307
I have well over 500 PAR near the top of the tank and close to 300 at the bottom so could theoretically keep anything.
The AI units will perform just as well if not a bit better as they have the newest Cree XP-G white emitters that have a bit more output than the XR-E ones I used. If I had the budget and wanted to just buy a fixture the AI would be my choice. Just couldn't afford those prices for a 4 footer so went DIY.