Well had a go for a couple of hours and not that impressed

I'll start with what I like:
1. At night with the IR scope on a sniper rifle hitting people is satisfying the way they die. If they could make Arma 2 better this way it would be great! In Arma 2 people get shot, sit there, then die a second or two later and just fall down.
2. The animation and reloading animations are a LOT better than Arma 2. Reloading a missile for example and general gun models.
3. Did I mention its satisfying shooting people at night with a sniper scope?!
Now what I don't like:
1. Helicopter sounds. The helicopter normally gets almost right above me before I can hear it and it just sounds weak. In Arma 2 you can here the digi-digi noise of the rotars in the distance and when they pass over you it sounds awsome!
2. The sounds. The explosions sound muffled and not too impressive. In Arma 2 when you fire at the distance the resulting BOOM a few seconds later sounds amazing.
3. The enemy AI! Enemies are so dumb

I've only been playing the campaign in hardcore mode and they seem to only work in groups of 4 or so. If there are loads about only a few will engage whilst the rest are running around. Once those people are dead and you shoot the others they seem to realise something is going on and come in for the attack.
4. The friendly AI! One example, on the second mission I ambushed the convoy and stole a jeep to drive us to the first checkpoint. We were ambushed by a load of people so I stopped the jeep behind the hill, jumped out to order my troops to disembark and they IMMEDIATELY jumped in the drivers seat when I jumped out and drove off down the hill towards the enemy and died. WHY did they get in the drivers seat?!
5. Fixed view forward in vehicles. Shocking. You can't see whats to the left or right of you so I end up turning and hitting rocks or bouncing around when I hit a tree. Even in BF2 you could look around the vehicle to look left and right at junctions. You also have no idea if your teammates are in the vehicle yet when in Hardcore mode. They don't say they're aboard or anything so I just get out and look at the vehicle as you cant look around the inside. Same when in the back of a helicopter. You can look a bit to the left and a bit to the right, but not much movement at all so you can't watch the baren countryside flying past.
6. In hardcore mode it should still tell you the current weapon you are using and what firing mode you are in. Hide the amount of ammo fair enough, but in real life you can look down and remember if you have the grenade launcher selected or are in semi/auto mode. With no indication what mode you are currently in its frustrating.
7. Moving whilst selecting a weapon! Why do you stop moving and cant even look left and right whilst the weapon selection box is up when you roll the mouse? I'm assuming this must be a bug of sorts?
8. Checkpoints. In the second mission on hardcore I've destroyed the first missile launcher which takes about 15mins, but it doesnt have a checkpoint save? Then you take a couple of bullets and die on the way to the next checkpoint and have to start from the VERY beginning of the mission again? Are there no saves at all in hardcore mode or something? I prefer playing in hardcore so why not allow me to have checkpoints + max realism the game offers? It's unrealistic to go 30mins between checkpoints in a game where one bullet can kill you and your friendly AI are so stupid that I basically leave them in "follow me" mode.
9. Atmospheric sounds. As mentioned before there arent really any. You hear your people saying "Enemy helicopter 200m north" but you can't really hear it as it's so faint. It then comes over and you can hear it but it sounds awful
10. No visible damage on vehicles at all so they all look pristine.
11. Flight model of helicopters is shocking and they feel far too light.
So in conclusion - Shooting stuff at night is satisfying using the heat scope, but everything else is sub-par really. I've given up on the campaign and I'm going to just make a sniper mission at night time! How PC Zone gave this 90% I'll never know :S
It's not a totally shocking game - The mission editor seems comprehensive so should be fun messing about in vehicles, making battles, etc using that, but the main game itself is quite poor. There are aspects of the game here that I prefer to Arma 2 (such as night heat scopes, reloading animations, the gun models, etc) but I prefer Arma 2s overall game mechanics. Arma 2 is far from perfect however and that game has its fair share of bugs too.
If you could combine the two you'd have a great game, but seperately neither are top notch, but I'd go with Arma 2 because the map is a LOT more detailed and the sheer array of weapons on show there is great. Multiplayer is also a lot more hectic in Arma 2 given the huge maps and numerous players on them. if only they could sort out the gun models, poor performance and graphics glitches in Arma 2 it would be awsome. I've stopped a few times in Arma 2 and thought "Wow that looks amazing" whilst looking at scenary, but I haven't done that in Ofp2 but to be fair to it the game runs very well on max detail and the buildings look better!