WP and Roy are correct, for most situations.
The only exception that I've found is for my post hole digger. I have to adjust the lift arms as high as possible to lift the auger off the ground.
Roy,I've read of similar situations (on TBN) in which a small CUT or SubCUT couldn't lift high enough for some implements...
For me it depends on what I will be using on the 3 pt. hitch. I adjust the arms so the implement clears the ground with room to spare when the tractor is moving. Not all of my equipement has their connection points at the same distance from the ground.
Ed