Actually not the case in my experience and it is has to do with implements that work soil in the field that impose variable resistance. Because the HST does not possess equal torque with DT, what appears as equal is not actually the case. So the argument that HST with CC matches the DT is not about "easy" but rather truly equal in context.
I've farmed since I was old enough to reach the controls and the treadle pedal/cruise control applications are simply not the industry standard in agricultural settings. This can actually be visualized when using planters or seeders, drills. Variability can be observed at points along the path of such implements and while this may not matter in small applications, large tract farming makes an HST with CC undesirable.
The HST's features seem quite suitable for a chore tractor or home gardens, but the application is not equal in all instances for the reasons noted. The tractors being discussed in this thread would certainly not constitute large-scale considerations that are normally handled by JD 9620s or 9-640s anyway, so it's really of little consequence for the prospective buyer who made the original post. My point was that the two tractors are simply not equal in the regard mentioned. Whether it matters to the buyer may be irrelevant.