An Irish Setter as a hunter takes a big dose of romanticism. I'm not saying that there aren't a few out there that do good work in the field, but rather than take the chance of beating one's head against the wall trying to disprove conventional wisdom, push your friend to a short-haired pointer, a Lab, or any of the other breeds we know work. It just makes so much more sense.
Maybe I'm just bitter. I let a friend bring an Irish Setter on a hunt once where I knew pheasant abounded. We could keep track of the dog by the birds that were getting up a quarter to a half mile away. It took about three or four hours for the hound to tire enough that we could sneak up on him, collar him, and drag his sorry ass back to the car. The only time we ever saw him, actually saw him the whole day, was when we let him loose and when we kenneled him again.