My family had two Irish Setters when I was growing up; the first one from show lines and the second one from working lines, and there was no question which was which based on their coats. Neither was terribly smart but they were both wonderful family pets. Neither had anything close to resembling a mean streak, but both were quirky. The first one was quirky in a high strung and nervous kind of way (completely fell apart during thunderstorms, fireworks, etc), but I don’t recall it was to a degree that was unmanageable. The second one was less high strung but very hard to contain. We got the invisible fence when it first came out on the market, and that dog figured out that if she tilted her head a certain way, the collar prongs would lose contact with her neck and she could run right out the driveway to freedom. And she would literally run around the neighborhood for ten straight hours before coming home. Seriously - every time.
About a year ago I thought I might want to get a second dog and I found an Irish Setter breeder close to me so I put myself on his waiting list, but by the time he contacted me to tell me he had a puppy I got cold feet only because I didn’t think it was a good time to bring a puppy/second dog into the household, so I declined. It had nothing to do with the breed.
The barn I grew up at had an Irish Setter that was quirky like my family dogs at the time. The next barn dog was a Gordon Setter who was a big old lovable goofball. I have an English Setter now who is the absolute sweetest, easiest dog ever but she does have a bit of a nervous streak to her. In my limited experience, the Gordon Setter is the most easy-going and adaptable of the setter breeds. I haven’t seen any evidence to suggest that any of them are particularly intelligent, but they all seem to be very people-oriented.
I wouldn’t discount either option until you are sure what you want.
