Jim,
<font color="blue"> The bucket goes down slower if I do go into float. </font>
Roy's description of "free fall" is accurate, but gravity still has to move fluid through the cylinders as the loader falls. The resistance is enough so "float" lowers the loader arms slower than actively lowering does. At least that's the way it is on my tractor.
There should be enough "throw" in your control lever so that you can control the speed. So far, it sounds to me like your control lever goes from no motion to full motion with too little room for partial motion.
A restrictor will limit your full motion speed, but won't allow any better partial motion capability. So, I'm not sure what the problem is, but your Cub dealer would be a good place to start. Of course, if you can make your loader drop fast enough to scare folks, a restrictor might correct or partially correct the problem.
OKieG