Let's say supers, like 110gr VOR-TX or 110gr GMX moving about 2100fps at the muzzle (approximately where it should be out of a 9" barrel). From a terminal ballistics aspect, what is a "reasonable" range to expect to be able to engage targets from, and expect both the trajectory and the results-on-impact to be acceptable. Maybe 200 yards?

Not max effective range, not max range period. Max you could count on a supersonic wunder-round being able to not have to lob it in like a mortar and reasonably expect the bad guy (or critter) to be reconsidering their efforts?