The Berkley PowerBait Sick Fish has fantastic action. A really fluid, slow swing of the tail that translates to a slight side to side action of the body as you make your way up the bait. The bait also tracks really well and doesn’t have the tendency to roll over when you speed up the retrieve like some soft body swimbaits do. I believe there are particular design features that contribute to these capabilities of the bait, starting with the tail.
The tail design is what first caught my eye with the Sick Fish. Where most soft body swimbaits have either a boot or paddle tail, the Sick Fish has a hybrid paddle tail with a little fin shooting straight back out of it. And the paddle isn’t flat, it has sort of a scoop to it. So what you’re left with looks like someone accidentally laid a knife sharp edge down in the spoon slot of the silverware drawer.