I don't own a Prune B, but given the chance, I would gladly trade my Gold B for this one hands down and with no regrets.
Yes I have in Clemence, like the bag you are showing. It's a deep rich raisin-ish colour but with brownish burgundy undertones. Not a bright purple, and changes colours depending on the lighting from it's lighter colour to very deep rich darker tones. Very tasteful and versatile at least for my wardrobe and style of living. I'm very casual. I'd never get tired of it.Have you seen it in real life?
I have a prune 30B and love it to bits. It's a highly versatile color, sometimes it looks like dark brown and sometimes the purple shows through. It's a neutral and goes with everything that goes with, say, black, but is so much more interesting.
I have a 40 prune Kelly. It's a great color.