If you are playing places where you amp is the source of your sound, a 5 is something that you're not going to be able to take full advantage of. Bass guitar cabinets don't reproduce the fundaments low on the E string of a 4 all that well, the notes lower than that on a B string - you'll hear something, but you won't really feel them, and you'll need a high pass filter to avoid the mud a bass guitar cab makes when it's driven hard at very low frequencies - it's not the fundamentals that are mud, it's that your cab can't handle them - that's where the mud comes in.
Anyway, if you play places where the PA is the main source of your sound, things change quite a bit. A capable PA with good subs and a few tens of kilowatts of power behind them is a much more capable rig than your bass amp, and will reproduce the fundamentals on your B string with ease. A 5 through a great PA is glorious.
I'm lucky enough to play places that fit this description regularly. All my gigging basses are 5's. I have one 4 string - a fretless that I'm emotionally attached to.
Anyway, if you play places where the PA is the main source of your sound, things change quite a bit. A capable PA with good subs and a few tens of kilowatts of power behind them is a much more capable rig than your bass amp, and will reproduce the fundamentals on your B string with ease. A 5 through a great PA is glorious.
I'm lucky enough to play places that fit this description regularly. All my gigging basses are 5's. I have one 4 string - a fretless that I'm emotionally attached to.