Most people put it as happy medium between BF (not the new ones, more like BF2) and Arma. Easy to get into but highly realistic with communication as the key. It is a PvP only game. The team is structured around several squads with squad leaders as the head honchos with their own mic frequency discussing broader strategy and tactics. Each squads have many specialist roles which are crucial in winning the game.
There are vehicles, too, and while there is not too many right now, anybody who is familiar with Project Reality Mod for BF2 will know that the end goal of this currently-in Alpha game will have vehicles up helicopters, main battle tanks. If you check out its reddit page or forums, you'll see that the game gets updated every month at least with big additions frequently.
It charges a fair price of 40 bucks .
subreddit
Squad Website