Ask HN: What are your thoughts on ultrasonic knives?

I liked this video - https://www.youtube.com/watch?v=bNwHDWlA7gE where Alex compares it to the revolution of reciprocating saws (amazing days we are in)

Previous HN discussion - https://news.ycombinator.com/item?id=43442107 I see why in commercial baking you might go with water jet, but I'm interesting in thoughts on ultrasonic knives and how people are using them and the possibilities.