Indeed, I think the days of ORK-DUB are gone. Over Christmas I had need to use the Aircoach from DUB to St Patrick's Quay. I have to say, its a pretty good service, is frequent, cheap and pretty hassle free.
You could probably save about 90 minutes by flying to DUB for an onward connection, rather than taking the coach. But if you are going to Dublin City Centre, the 0500 would have you in Dublin at 0800, or the 0600 at 0900, which you'd struggle to match flying.