We just went through this back in December and prior to picking out our new pup I was putting way to much on it and once I got there I just went with the one that felt right. The funny part was my wife and son picked Jackson out within a minute but never said anything. It took me about 10 minutes. If you have done your home work on the breeder any pup has what you want in them, now you just have to bring it out - well that is what they keep telling me. Anyway I picked Jackson because he was outgoing, investigated everything, interacted with everyone and he even stole my camera. He just seemed more even keel the the other two (I had first pick of the males). He has only been home for a month but he is every bit of what he was and coming along nicely. My Hannah who is 7 was an easy pick as I had the last pick of the females and she turned out good. My shorthairs I picked somewhere in the middle on both. All 4 pups had good lines and breeders which i why I think I was happy and successful.
Good luck to you.