Yeah I'll grant you it was fun. Once I'd 100%ed I turned on the unlimited dead eye and used the sniper rifle, as you can keep AIS even while reloading, meaning you can take multiple shots in slo mo. Now THAT's fun. You should try it. My favourite trick was shooting someone in the kneecap first which shot them up into the air sideways, then seeing if I could get a headshot before they hit the floor.