However, the truth is that you really do not need a 5 because all you really gain are 5 notes in a lower octave. They do sound better in some songs but one problem is that many people who play 5 string use the low B too much and as a result they just "muddy" the sound of the band.
I don't play a bass with a B-string just because of 5 extra notes. I like having more range in one position and I like to spread the notes out in chords. I used to read music in 1st position, now I do it in 5th. I almost always play the low E on the B-string. If your playng a 5-string just for 5 extra notes, your doing it wrong in my opinion. This is all just my opinion though.