Well, I used a corona mill for my first AG batch and a barley crusher for my second, which I did today. Both batches had 10# of grain.
My arm ached after the corona mill, but the crush was excellent.
The barley crusher ground the grain in 15 minutes but, at the factory gap setting, was too fine. I had gain bits in my wort.
With the Corona, I had some dust and some fairly whole grains, but no grain residual in my wort.
I will adjust the barley crusher to a more coarse grind next time and see how that goes.
All in all, I recommend the barley crusher primarily for the time savings.