Most of my darter experience has been with bigger darters, like Gibbs and Superstrike. With those, you do not feel any throbbing or swimming thru the line and rod. But as long as you can feel tension on the line, the plug is doing what it's supposed to do
You'll get the best result out of darters in current. Yozuris do have more built-in swimming action than classic darters, but they still need a little water movement to work at their best. Sometimes all it takes is just a little wave action. In flat water without much movement, a Crystal Minnow or a Tobimaru is a better choice.