It only adds to the "realism" if you are simulating sweating. The Army may be switching over to the IOTV, but I was at Ft. Lewis with the National Guard all weekend and I didn't see a single one. That was a great weekend, by the way. Nice review. I own one of these, and I have to say it's extremely comfortable. My advice is to put mag pouches as low as they can go all along the front of the vest. That way you can have a nice arm rest.
Since I have obtained somewhat of an infantry mindset from my buddy in the 116 Cav, I followed his advice and got rid of anything that had no functionaly purpose. It's just dead weight, and a heat hazard. Don't bother using the arm pieces, neck guards and nut plates. If you really want to be super realistic, then fine, use the neck and nut pieces; during the weekend I didn't see a single DAP(Deltoid Arm Protector).