As I said in an earlier post, I generally only use an open string "if I mean it," as per Phil Lesh. Those of us who play 4-string basses (in standard tuning), though, have no choice but to use the open E, even when we don't really "mean it." And, if you're like me, you use that note a lot. Sometimes I think that this might be the single best reason to play a 5-string....