I tend to disagree that the slower velocity load will have the 'same pattern percentage or fundamental density throughout the pattern.
All things equal (powder type, wad, shot hardness, barrel choke and forcing cones - my experience gives the slower/ower pressure load a slight advantage presumably due to slightly less shot deformation - and thereore 'flyers'.
Whatever opinion you want however, ou should be able to get one.
My only recommendation is to try 'em under controlled conditions, including recording velocities - and counting pellets...