OK, then if there's a housing issue that should give you time to budget accordingly. Some schools tell the Greeks AFTER everyone's signed housing contracts for the next fall that next fall will be deferred rush and they don't know why it doesn't go over.
Some of the big things are:
DO NOT enforce silence for an entire semester. (I think the new Green Book says 30 days is max) Too many schools w/ DR do this and it is not at all what DR is supposed to promote! Long silence makes the sorority members hate it, because they have to constantly worry that they "slipped," and it can come across as snobby to the rushees or campus in general because they don't understand the rules.
The whole point of DR is for potential rushees to get to know the sorority members as normal people, not just girls at parties.
Everyone else pretty much touched on the most important things. True, you're going to have girls coming in maybe having heard more talk about reps or HAVING reps - but to me, the knowing that on both sides, you're choosing who you want in spite of all that is what makes DR so so SO much better. You don't have to worry that the girl who loved you in rush and once she gets a bid and starts pledging, then hates the fact that you have 3 intramural teams and are all gung ho into sports. Because she's had a whole semester to observe you and know that info going in.