I don't know if it's because there weren't as many people playing it as normal crucible so the matchmaking was a little less strict or what... But iron banner for me and my clan has been 75% awful connections.
I'm not talking about a tiny disadvantage due to a person having host, that I can shrug off.. But it just seemed that so many games we played, our hits were registering later than they should have, whereas the enemy team seemed to be able to kill us with 2 mythoclast bullets, or 1-shot us with The Last Word..
I've had so many absolutely ridiculous deaths, mostly down to the poor way the game's netcode handles user hosted games.
See the video for a prime example. I'm running 20mb internet with 4mb upload speed, very low ping and haven't had this problem on normal crucible.