I'll start by saying that I love Casey's and I definitely frequent there more than any other bar in town. But the service is absolutely the worst around (outside at least, and I would not recommend going inside). Expect to wait 15 minutes to get a waitress to notice your table and then expect another 15 between ordering and actually getting your drink. Oh, and don't be surprised it your waitress confuses Smithwicks with Fat Tire.
That said, the drink prices are good (especially during happy hour), the location is awesome, and nothing beats sitting outside at Casey's on a nice afternoon/night.
I would not recommend eating anything that isn't fried (how is this place an oyster house?!), though it does have good food for drunk people.