Excellent, however, hard, and usualy you run out of ammo.
The only drawback I have to point out, is that I was out of ammo in many missions, and it is hard to find from dead soldiers. Although it is realistic, it is getting ugly when playing.
The missions are well designed, you can finish them in many different ways, and there is no "corridor" like in many other FPS games (MoH, CoD, GRAW, etc) and that is why it is categorized as Military Simulation and not just a FPS.
At the end, although it is ported from PS3, it has very few flaws that could be better implemented for the PC version.
For the MilSim fans, it would be a classic!