Has the GriGri taken over?
If you take your break hand off when the climber is already stopped it isn't a big deal but if you take your break hand and then he falls there is a small chance it may not catch or may be slow to catch. It's a dumb chance to take. I saw another device like the grigri but I'm not sure who makes it and it's smaller. It looks kind of cool. You can still get plates if you are too cool for new school. I like the grigri in case I chuck a rock on my belayer and knock him out.