But WHY??

It's simple, if you like the DV, keep it, if not take it off. It's that easy. I cannot think of ANY reason why anyone would want to choose?

Surely you don't think to yourself "I know, I fancy driving my car around on light boost and hearing it chatter today, no, actually, I'm now going to rag the tits off it, so I better turn my Dump valve on"