On a B3, the two manuals are actually much closer together than in the average two-stack keyboard config. Even when the top keyboard is on the flat surface of the bottom keyboard, the space from the top of the keys on the bottom keyboard to the top of the keyboard coupled with the space from the bottom of the top keyboard to the top of the keys is considerably more than on a two-manual organ. Also, on organ my right hand is divided between the upper and lower manual and usually only plays in 'spurts'. I'd hate to play full time with my left hand in the 'elevated' position as in typical 'arranger' playing. Lastly, my right hand is stronger than my left AND more dexterous. If you're eating Cheetos while watching a porn movie, when it's over, note which hand is orange-colored. ...unless, of course, you're a 'lefty' .

chas