The youngsters I play with prefer to leave it in, but I prefer it out. It's typically 2 of them and 1 of me, so we just leave it. I think I putt better with it out, but typically putt the same with it in. Mind games.
I really hope we see a resurgence of them. I am a massive fan of them, and greatly prefer one over a 3W. Part of the reason why my SLDR Mini Driver still finds its way in to the bag.