I have both the b and c as well as the mel
I use them both in my classic rock covers band ( purple, whitesnake, rainbow etc..), and Ozzy/ sabbath trib to give the thickness that keyboards can give.
I find the work best sent to PA, rather than through my bass rig, and have built simple systems for this to work.
combine them with a freeze type pedal, and you could have keyboard pads for days lol