I've found that Iron Banner has some noticeable differences. While the difference in gear/level may seem non-existent, I've noticed myself doing much worse in my IB matches than in the Crucible. My theory on this is that the level tweaking has just enough of an effect for grouped enemies to team shot me with great ease. This caters to defensive play, as well as strategic coordination with a fireteam. I'm a very offensive player who tends to lone wolf it in most situations. I definitely go down much quicker in IB when I attempt my usual crucible strategies. This forces me to play defensively which has shown some improvements on my end, though the real advantage goes to whoever has coordination.