Q: what are advantages to playing 5-string bass  instead of a 4-string bass, and should i throw my 5-string bass away? or sell it
A: the advantages are the low notes between B and E. you can certainly live without B, but if you really have to live without that Eb, you could find yourself in some sad situations. however, if you are clever, you can learn to survive just fine. after all, everyone got along just fine until the 1980s. personally, i use at least down to Db quite frequently. In modern times, i have found that many players use an octave doubler (with a 4 string) when they need those notes. however, some players choose to use the octave doubler irresponsibly, and they go way below B, resulting in a rumbly mess, and also being punched in the face by me