Anyone use one in their live setups? Been looking up favourite bands and stuff, the most common one I've seen is the Radial JDX (red box) one, apparently gives cleaner signal and makes the sound guy's task easier when mixing your guitar. Also stops bleed coming from any other source and I see the point of not wanting the guitar amps blasting into the vocal mics.
So do I actually need one? Or is it just an optional luxury?