Professor Moriarty wrote:
Constitution-class starships and Galileo-type shuttles used flywheels or gravity generators or something else besides RCS thrusters for fine adjustments to course and position. As it turned out though, field experience showed that this mystery technology was inferior in performance to good ol' tried-and-true thrusters.
Hmm, yeah, I'll buy that for a dollar (to steal a phrase from "RoboCop").
Seriously, that's not a bad idea. Kinda' meshes with my own thoughts about different contractors getting the job and pushing their own designs and technologies. Who knows, maybe the TOS "E" had a fairly heavy Andorian or Tellarite influence that lost and went back
to Earth based industries by the time of TMP.