Rear suspension too stiff

I never thought of it before, but to me it makes sense. Unless its a bushed mounting point, I guess, nothing in a suspension should be "fixed" or held in place without some type of movement. Those individual leaves still move, I think all the center bolt does is keep them moving together. It makes sense that if the u-bolts are too tight, you would be clamping the center of the springs together and not letting them do their full job of suspension peices. Hmmmm...pretty awesome idea.