FutureCadet,
My DD(now c/o 2014) and DS(c/o 2016 appointed) both had interviews for SS. DD was face to face but fairly informal. DS was by phone. In either case, I would take it seriously. When DD went for the interview, we were very new to the whole process, so she went in jeans and a nice shirt (they met at a Starbucks for the interview). We took into consideration the location of the meeting, but by no means did we have the information contained on this site. With DS it really didn't matter. In my opinion, as long as you did not show up in clothing that was in bad taste, you should be fine. A polo and slacks would work. I wouldn't stress the interview either. From what I remember it was some pretty basic questions.
My DD(now c/o 2014) and DS(c/o 2016 appointed) both had interviews for SS. DD was face to face but fairly informal. DS was by phone. In either case, I would take it seriously. When DD went for the interview, we were very new to the whole process, so she went in jeans and a nice shirt (they met at a Starbucks for the interview). We took into consideration the location of the meeting, but by no means did we have the information contained on this site. With DS it really didn't matter. In my opinion, as long as you did not show up in clothing that was in bad taste, you should be fine. A polo and slacks would work. I wouldn't stress the interview either. From what I remember it was some pretty basic questions.