It is very good. I baby sat it for 5 hours and only detected two problems.
One, at one point shift drop wasn't working properly so it kept trying to use logs on logs.
Two, the southern east most willow tree glitches the bot. for some reason if it ends up over there, it will just stand there for all eternity while not chopping and needs to be manually moved. I fixed this issue by zooming in on the screen and putting my character as far west as possible.