Since I grew up around a shop owned by my father who was the first man in Nashville to work on automatic transmissions in the late 1940's, I know exactly what you mean. The HydraMatic was one of the best-engineered automatic transmissions ever, and most of the so-called "improvements" in later designs were for driver comfort, not actual better operation. People didn't like the positive shifts the early ones had, which led to changes that allowed for soft, mushy shifting.
Dual-range transmissions even had a feature that allowed the rear pump (driven by the driveshaft) to take over the hydraulic demand, and take the load off the engine-driven hydraulic pump. This reduces the power consumed by the transmission pretty dramatically. That's only one of many details about this transmission that puts it way above a lot of others, quality-wise.
Jerry
