Played Iron Banner yesterday as a level 21. Believe me, I especially feel the level differences when playing. I could barely scratch a level 29 Warlock who ended up on the other team for a few of my matches. I had to get really lucky tricking him into entering my Ward of Dawn when I had a shotgun just to even have a chance at taking him down, which by the way didn't happen often if at all. Otherwise even if he was unaware and I got a few first shots with an Auto Rifle on him he'd just turn and down me like it was nothing.