I ended up a bit disappointed with SOCOM 4. Seems not even the greatest squad-based tactical shooter series I've ever played can escape the evil clutches of "casualization". Squad orders have been cut drastically (no longer can you tell them to throw grenades, go to a specific way point on the map, or when to "hold fire" or "fire at will"), my teammates can't stay the fuck out of my line of fire or go a single mission without getting me compromised because they won't stay put where I tell them to, and the "battlefield romance"-like bit that the player character, Cullen Gray, had going on with his female teammate was really fucked up and out of place.
The gun situation was something else, though. In the previous games, you could collect and use ammo from dropped weapons as long as they were of the same caliber, but they went way beyond just that this time. Now, if you're carrying a Negev, you can use ammo from dropped RPK-74s. If you have an M60, you can use ammo from dropped PKMs. If you have a FAL, you can use ammo from dropped M4s and AK102s. If you have an M4, you can take ammo from dropped AK102s, FALs, Mark 17 SCARs, and the scant few ACRs (which, BTW, can also take ammo from dropped AK102s and FALs) you find in a couple of levels, but not F2000s or FAMAS which use the same magazine as the M4. If you have an MP5, you can use ammo from dropped MP7s and P90s. What the hell?
You can still put optics and suppressors on and off your guns at will, but once you unlock bipods, foregrips, or grenade launchers for a gun, they're permanently attached (unless you pick up one that doesn't have it off the battlefield). And the fact that the grenade launcher on the M4 in this game was a fucking GP25 instead of an M203 really pissed me off.
[/rant]