I tried to test the rotating-resistance of two 727 transmissions and a A500/42RH I got laying around by grabbing the inputshaft with 2 fingers and rotate it clockwise;
Both the 727's rotated fairly easy but the A500 took way more effort and required a firm grip to rotate.
Something is not right with the a-500 or the 727s, too tight of clutch clearance or end play or... when a 727 and a500 are properly assembled the a500 shaft is always easier to turn. At the other end of the trans is a different story as you will have an extra set of clutches and more weight on the a500 output shaft but the extra drag there is more than offset by the lower RPM in %99 of cases (for example a 4cyl might not have enough spare power at a low RPM to overcome the extra friction/weight).
