As Hughes500 hinted, it has a fully articulated rotor head, so the manoeuvre tolerances are greater for a start. That is a world of difference.
The governor/correlation relationship in the Robbies only offers limited exposure to the relationship between ERPM and RRPM. This can really be drilled to intuition in the 269
The power range used in the 269 is greater (it is not D-rated) and you can more easily simulate power-limited situations.
Bringing the aircraft into balance and trimming the cyclic are good fundamentals for other larger types. The Robbies come into balance pretty much on their own and there is no cyclic trim.
It is more robust and has more energy in the rotor. The margin of safety is greater during autorotation meaning there can can be more tolerance of error. This margin can be translated into more exercises getting done which don’t always have an eye on the thin RRPM margin and the risk of mast bumping.
It is easier and safer to demonstrate t/r problems..