Are you serious? I've experienced abysmal AirPrint performance with the J430W. Completely unreliable. Sometimes the iPads pick it up, sometimes they don't. I ended up just deleting all the WiFi information and using Printopia instead (defeats the purpose of AirPrint, but at least it works). Printing from iOS devices is rock solid now, no thanks to my supossed "AirPrint compatible" printer from Brother.
If I had it to do over I would buy any other brand but Brother.
Never again.