I have heard Christian music that is good, and Christian music that is not so good…but it gets air time because it delivers the Christian message. Rap can be used to effectively portray the Christian message, but it always helps if it is well done. My favorite “Christian-esqe” rap song is actually out on the secular market, but delivers an undeniably pro life message “Can I live” by Nick Cannon. I also know that Father Stan Fortuna has had some success with his music, although I haven’t had a chance to really listen to him.
Keep working on good music and keep doing God’s work. I have no prob with Catholic Rap, as long as its good!