I am a 25B (reserves). I had a bachelor's degree before I enlisted, so I can't tell you much about the GI bill except that they gave me $9800 which I haven't done anything with yet (maybe use it to buy a house, combined with the VA guarantee). I can tell you that any signal MOS, especially 25B and 25A (signal officer) is in ridiculously high demand, so you will be deployed at least twice. I got home from training and six months later I had been cross-leveled to my current unit, which just so happened to be in Afghanistan at the time. So, expect to spend two of those four years in Iraq. If you're cool with the risk, do it. You will learn a lot and meet some great people with some great connections to civilian jobs. And after you're done with active duty, you can go back to Iraq as a civilian and make 5 times as much as you did when you were a soldier, but you won't get to carry a gun.