Well, I bought the game (PS3) after reading this thread. I have to say that I'm not that impressed so far, though.
The patrol jeeps are highly annoying and seem to appear out of thin air. The AI takes a few too many bullets (on normal) before dropping. Even worse, if the baddies are behind cover, like a tree branch, they can hit me but I can't hit them with my 50cal mounted machine gun. Pretty darned frustrating. And I can see the malaria thing getting extremely annoying.
On the upside, the graphics are freaking stellar. One of the best looking console games this gen. The missions are fairly fun and I'm a big fan of the buddy system.
If I had to rate the game based on what I've seen so far it would be somewhere between a 7 and an 8. Hopefully it picks up and the missions get more fun with bigger weapons. I am looking forward to mortars.