He's right that you'll get a cooler better looking color, and have more control of what you want. Problem with this is that you'll have created a tri-coat color that will be difficult to match. You see, if you need to a repair later down the road you'll have to get the exact same amount of pearl,flake,etc on the area to be repaired in order for the color to look right. You just need to decide is it worth it. I say YEA, putting flake/pearl over black looks killer if done right.Just put some Pearl in the clearcoat. Over black
For an even better color.