Touch them, feel them, become one with them
My first gun was an 870, I loved having it but I couldn't hit anything with. I loved the feel of the forearm, but other than that the gun just didn't feel comfortable to me. My buddy let me shoot his 500 and I loved it. I could hit almost anything that was past my bead, but unlike the remington the forearm didn't feel as good. The safety was in a more comfortable position and it seemed like the stock just fit me better out of the box. I am not knocking Remington, damn fine guns, I just prefer a Mossberg from personal experience. The only advice I can give is find someone with each gun and shoot a lot through each of them. There is a lot of bias towards brands around here, but that's life, people have their favorites and they will push them. Just find what you like and enjoy it. If its not comfortable to shoot recreationally then how can it be comfortable to use to save your life?
-My 2 bits-