I picked up a Jaccard last week to mess around with and to my surprise they do work very well.
I used it on a top round steak about a inch thick and used the Jaccard on both sides a few times east and west then a few times north to south. I grilled up the steaks and I read that it will also make the steaks cook faster but I am not sure I beileve that. The steaks did come out super tender. I picked up a few NY Strip steaks and I will see how it works on them.