Gah, nonsense. Show me a game that doesnt have cheaters.
Most servers have the "Checkruntime" option set to 2, which doesnt allow you to join with the modded files. And the biggest forum/download center for the mods doesnt allow mods that tinker with the flightmodel or other kind of cheating. The worst enemy of the great MP of IL2 is currently the tossers who use print screen to lag the others, not the ones who use them mods.
Tho, like we've seen in an private games with Hunter, it sometimes messes up the coop games for the one using the "main mod". But this have only happened in a custom made mission, online campaign works well.
Just my 2,000,000€ on this.