I have been off Ironsight for a while as I bought CoD MW.
So far I can tell you...
1. If you have ping 50ms in Ironsight, you will have 80 to 90 ms im CoD MW. And even it should be 0,05ms difference, it is actually about half a second of advantage.
Never blame Ironsight netcode again.
2. You hate drones in Ironsight? Dont even try CoD MW Multiplayer, killstreaks and spawn kills prevail the winners.
3. You dislike campers? 99% of them camp in Cod MW.
Ironsight is lighting years ahead CoD MW multiplayer game and servers, and its free.
Luckily there is fun Co-op mode in Cod MW, other than that game is trash that can't be bigger.