I dont think there is one rule of thumb, every unit might have its preferences....from my limited personal experience so far in talking to units, i remember one unit told me they wanted their personel to live in a one hour radius of the base, while a friend of mine just got picked up in a west coast guard unit, and they live in the midwest region with me....so just make some phone calls and find out what each one wants....so far from the 15 or so units ive talked to, only one wanted you to live in a certain area...the others didnt specify or it didnt really matter......hope that helps....maybe some current members of some units can give us some inside info on what their units prefer.....