FC2 is very hard-core. The pace is slow and deliberate (until they spot you!), like in Ghost Recon tactical shooter. FC2 is also an open sandbox style of game play like GTA 3 & 4. It's not about going from very scripted level to level spraying bullets as fast as you can push a button (you can, but won't get far in a realistic way).
You need to carefully plan your strategy using different environments, guns, vehicles, etc. It takes practice to learn how to be invisible without a nano-suit and play the game correctly. I found this engrossing enough to want to play the game correctly-not arcade style.
The biggest complaint is fast checkpoint re-spawn time, but fixing the car is also unrealistically fast (both can be slower). Also, why is everyone your enemy if you are working for a faction? FC2 is very immersive with a large & detailed environment (with a bus to help you get around quickly) and a story worth telling. I actually like this style of playing and I hope FC3 is like FC2, but better.
my 2 cents..
[edit] Yes, there are some rough edges like the AI could be at times better as nebun said. Hope this gets fixed.
If you want FC3 to be more like FC1, its been done already - It's called Crysis.