I've been playing for a bit but I havn't left the first area much yet. I'm patched up so I don't know how things were before but at during the first warehouse mission on Stalker Difficulty, I managed to die four times before completing the mission. I found it near impossible to complete with the starting pistol so I ended up just waiting for the bandits to pick off my buddies then I robbed them of their shotguns and make a long battle of hiding around corners and blasting bandits in the face until they all died. For awhile this was how I had to deal with human combatants, that is until I upgraded to a better pistol. Once I could do a little more damage, I found headshots more worthwhile going after... although I find no trouble with running out of ammo, at least not here. There's so many bandits (and dead stalkers) around, I tend to leave a stash of 500+ ammo at the trader while taking my load of +P+ 9mm around. Especially the bridge... 500 so I can pass AND raid the bodies of the morons who tried to kill the military? Pfft, it's like paying me to pass through with how many guns, bullets, and bandages I pick up.

I know stalker isn't the hardest difficulty, but tell me ammo becomes more scarce the deeper I move into the zone. Right now I could easily just keep making rounds around the first area and save up enough money to buy the best gear from the trader. The Ai is becoming more predictable too. The animals were always kinda dumb, but the current bandits seem to just make dumber choices than the first batch I fought... Maybe my inexperiance then made me feel they were better than the ones I face now?

I did have a hard time taking out the trio of military grunts, and it did end up costing me all of my grenades, some medkits, and a great deal of ammo, but the reward for killing them wasn't that impressive. A few rifles weaker than the ones I pick up from dead bandits, but nothing stellar enough to make it worth taking down the grunts.

I suppose the game just isn't that rewarding when you preform daring acts. That's one thing I did like about Oblivion with OOO mod running, if you managed to take down a crazy powerful enemy, you were rewarded greatly.

EDIT: Quick Update... I decided to see if there was a difference between stalker difficulty and master... so far there isn't much. In fact... Master seems a little easier. Partly because yes, 1, I have experienced some of the game's events before, and 2, well I don't know it just seems easier. This time around I told the guys I would go to the warehouse solo. I managed to knife kill 6 of the 8 guys before the last two noticed me and opened fire on my position.