One thing I found kind of funny was one of the shootouts near the end, where you're with both the female partners (in some sort of indoor "arena" like area with a sort of big statue thing in the middlee). I was in a good safe position on top of the entry staircase, but ... I ran out of ammo (that's the problem with shooting from a safe location, it's often hard to stay stocked up)!
My two partners kept shooting like crazy (I guess they never run out), but they never, ever, seemed to kill anybody, and the bad guys just kept pouring in... do shots from your partners actually have any effect? Or, do they wound but not kill? I seriously waited like 30 minutes (used the bathroom, cooked a snack, ...) while my partners were just pumping endless shots into the mass of bad guys (only some of who were armored), and as far as I could tell, not a single one died. [This is very different than Uncharted 1, where often you could just hide and let your partner kill everybody!]
[I eventually gave up and started running down into the mass of baddies to grab ammo (and then back to the hidey-hole), but it took me forever to clear that area...]