Well, I think this has been answered thoroughly.
Anyway, I highly recommend one. I have a S&W 625MG in 45LC I had cut for moons so I could shoot ACPs. The ACPs are about the only rounds I fire through it now-a-days, since they're so much cheaper.
Now if only I could get my reloader set up again...
“There are three reasons to own a gun. To protect yourself and your family, to hunt dangerous and delicious animals, and to keep the King of England out of your face.” - Krusty the Clown