I own this game, I own it because I have a friend who plays it online too, we drive tanks, jeeps, helicopters, boats, pick-ups, bikes, you name it, we have driven it. And we usually end up dead in them too, dead but still laughing. This game is like supporting West Ham football club, sure a lot of goals go in, but when you do get one, its like the best thing in the world, worth the wait. Its HARDCORE, sometimes you will spend 10 minutes driving a jeep to the battle with your pal on the 50.cal machine gun and another friend in the passenger seat, only to be shot by a tank from 1 mile away, you wont even hear it coming let alone see it. But the times when you make it, burst through the enemy lines, take out that tank with an RPG while you friend lays down covering fire, then stealthily steal a helicopter from under the noses of the enemy is brilliant. If you dont have patience, if you dont like tactical shooters, you will fail, you will cry, and you will complain. If you can handle this, you just might have some fun.
Technical: The (draw) distance that you can see the landscape and objects can be immense, I was not exaggerating about the 1 mile or 10 minutes drives! (small distances, best to learn to fly at some point in training, tip: gentle movements of the mouse, dont overcorrect!), the game is made on 2 massive islands with varying terrain from mountains passes to wide grassy fields, forests to urban city areas and coastal crossings, you can go anywhere and are not restricted at any time but missions are usually concentrated on certain (large) parts of the island.
Buildings and bridges CAN be destroyed!, all you need is a lot of C4 positioned in a realistic manner, armoured vehicles can drive through things you might expect them to, trees, small walls, all those annoying bushes that other games wont let you drive over! Even some jeeps can eventually take out a bush after a little nudge. You will need a fairly nice set up to enjoy all the extra graphical touches thay have added to the game, contrary to former opinions it does look good if your PC can handle it, that being said, the lower end is still catered for. Patch 1.08 smoothed things out for me by a quarter.
Singleplayer is difficult, the A.I. will at times be mercilless, dont fret, use your wits and direct you squad using the in game squad commands, there's the great and easy ability to tell your men which posistion to sit in vehichles, or even which part of a building to wait in ambush for passing tanks and foe's, formations can be set, and also states of awareness can be given, and even after that if its still too hard, get your mates (plurel) to join in and help in CO-OP mode.
Personally I think online is where its best, you can have over to 100 players at one time! usually ends up at about 60 though, The community made missions are great, especially "HOLD" maps, its just a case of getting to the battle zone and keeping those areas for as long as possible.
So it all boils down to, buy if your HARDCORE and need a challenge. Think hard if you wont ever have the time to enjoy it, and are usually an instant, arcade player.