I was planning on buying the 5 string Ibanez ATK305 until the guy at my local music store told me how 5 strings were going out of style. He advised me to be sure I want a 5 string before I order it, because if he gets it and I decide against it, he won't be able to sell it. Can someone give me the run down over why one might chose a 5 string over a 4 string, and vise versa. And also explain this whole going out of style thing?