Shift speeds

The 727 is a beefy trans but Ch made a monumental error in the design. The 2-3 shift: trying to 'time' the disengagement of a band that is underload & then have a clutch engage with perfect timing so that there is no flare up or bind up is an exercise in futility when you also factor in varying speeds, fluid pressures, friction material wear, etc.
Ch fiddled with varying ratios of k/d levers, but it is the concept that is at fault. And having a band try & stop a huge, heavy, spinning drum.....At least they made the adjustment external for the inevitable wear.
GM got it right, they used sequential clutch application.