Engine sound - I turned up the general volume in windows, dropped all the components accept engines, and I can hear the engine quite well. Punch in the AB and you hear the sound increase in amplitude as those two turbojets wind up. You see the exhaust of incandescent gases when the AB is full on. Audio warnings - great. I don't have to use the rwr to know where is what most of the time.
Terrain features are as realistic as looking across the actual Iraqi desert.
In-flight refueling is one of the more challenging sims, in this game. I could feel my adreneline surge, when my aircraft signaled a Surface to Air Missile inbound. I see why Jane's is the foremost authority in simulator games. Totally mind blowing. Just like reality.