[omega3]

The tomato test is disingenuous - no one slices a tomato by pressing the knife straight down - you slice it to break the thick skin and follow with a slicing motion. The rest of the graph basically shows no difference between the force used for ultrasonic one and standard knife used inefficiently?

[rkomorn]

And yet, when people like to show off how sharp their knife is, dropping a tomato on it (blade-up obviously) and watching the tomato split in two is one of the favorite tests.

Probably (and precisely) because you can only achieve this with a knife that cuts very well.

[account42]

That's nice and all but I don't think you want to be the guy that brings an ultrasonic knife to a knife sharpening competition.