I've had 3 hyroads but not a pearl hyroad. I'm assuming that the pearl is cleaner and longer with a sharper backend. The hyroad will be slighly earlier and more of a rounder backend (not arc) less sharper or less quicker off the spot than the pearl.
If you like the pearl and plan on getting another, why not surface one of the pearl to slow it down off the friction? or forget the second pearl, unless you're going to replace it, and get the hyroad.
don't put too much thought into it. I've had two of my hyroads when there was no pearl. One had a smoother surface and the other with polish with 4K underneath. I had a one two punch......