With people's experience using a NAS which one seems to be the easiest to use? I am getting this for a friend of mine and he wants some things to be able to do. He wants to be able to access with his iPad at home and on the road. His co worker needs to be able to access it when he is on the road also from his laptop. The user interface needs to be user friendly if that is possible. 4 bay would be good so raid 5 can be used. Anyone care to give their 2cents. Thanks