I use them to dump, they have been good to me. I have picked up a couple of boxes of halfs there, just to see what they would produce. Got nothing.
I have picked up dimes, nickles, and pennies there. 50% of the dime boxes produced silver. I have gotten a few war nickels, and a buffalo. The pennies usually produce pretty well. I generally get 10-15 wheats (last box gave up a 1913) and 4-6 nice "s" mints from the 60's.