i used to play a 4-stringed when i first started off. Need more low end range so i bought a 5-string next, after that i'd been a pure 5-stringer. There are some advantages and disadvantages to 5-stringer compared to 4-stringers or some call it extended range instruments ... meaning 5-strings or more.
Advantage
1. You get more range especially lower end range/or higher end if you string it with a high C. I'm a low end person, i love my low notes. I think it's an advantage if you learn how to utilize your low notes thus extending the spectrum of your band/music you are playing. Mad contra bassist include anthony jackson, yves carbonne, bill dickens ... check them out ..
Disadvantages
1. You'd find it harder to slap and move around, e.g. double thumb, linear slapping and stuff but after a while you'll get used to it, i'm used to it now ...
2. Playing will require more detailed techniques for string muting, now you have a low B to worry about that goes .. "hummmmmmmmmm" .. so it's irritating if you dunno how to string mute properly
3. Scale length, you'll find it a challenge to find a decent 5-string bass around with a 34" scale due to physics but it's not hard. Especially looking for good extended range basses, the main issue is clarity, if your extended strings are muffled ... really no point having it ...