I know a guy that knows a guy
that has used one of those. That brake will save your fingers but destroys the blade and brake in the process. Still, I'd rather replace table saw parts than get my
weiner finger stuck back on.
One problem he did mention is using lumber that isn't totally dry. A few times I've bought green treated lumber from Home Depot and it was a little wet. He said that stuff will trip that blade every time.