Hello, I'm a long time lurker (actually since before 2005, that's just when I decided to create an account).
When comparing ArmA to say, CoD or Battlefield, it's pretty clear which feels more realistic, but what do you attribute this to?
I don't think you can honestly say it's the tank / helicopter / plane physics & weapon systems, can you? Those don't seem vastly better than Battlefield to me. Feel free to disagree there.
I think it's primarily attributable to:
You die easily.
The vastness makes dying SUCK, especially when you just travelled for five minutes. It fosters an entirely different mentality.
While tanks and planes and helicopters aren't really realistic on their own there is an interaction between them that's missing in most other games.
Disagree entirely? Other points?