Slice!! I've had mine since they first came out, and it is great! Somebody said that after awhile the cuts go wonky...that is just the charge winding down. I use mine plugged in. If that's not possible at a crop, I have always been able to find someplace to plug it in, then when I need a cut I bring it to the table. Then I plug it back in when I'm done.
If it's fully charge I don't have a problem with wonky kuts.