The AK-47, the automatic militant's weapon (I want to say AKS-47, but that's probably wrong), and the insurgent LMG (no idea about it's real name) all have similar, and very good, low profile iron sights.
In honesty, I think most of the insurgent weapons outstrip their marine counterparts (I hate the M4 iron sight with a passion).
My only two real wishes would be
a) Some kind of healing/recovery mechanic. I know that breaks the realism, but as the game doesn't account for long term combatant survivability, there's currently there's no incentive to help injured or incapacitated friendlies, which also breaks realism. So I'd rather break realism in a way that would be more fun and more encouraging to teamwork.
b) Some way to create fireteams/squads and have squad only communication. High communication teams are much more fun and effective, but the voice channel only has so much bandwidth, and it gets really cluttered at times.