Most, if not all developments in your time frame have been more about fitting existing ballistics into smaller actions, AR platforms, etc. Ballistics, aside from improvements due to new propellants, have remained pretty much the same. Better bullets have extended the usefulness of many rounds a bit and faster twists allow longer bullets to be used for increased range.
All of that aside, The 6.5 CM is the one that appeals to me most, even though I don't have one, and likely never will.
