This is simple. If you like to shoot off hand with your elbow up, conventional; if you like to shoot with your elbow down along your body thumbhole! I get the feeling that most people ask this just because of how they look and are worried about resale possibility, because they are completely different when shooting and you are going to want one or the other depending on shooting position, and nobody is going to tell you what is more usable for your needs. You already know.