So the same as for most of us average amateurs then
Thinking about this, there must be an overlapping, blurred zone where practice takes precedent over theory and real atmospherics make the differences irrelevant, or tips the balance one way or the other
For example, between 6 and 8" in average seeing west of the Dividing range?
Is this what is meant by "diffraction limited" ? And what stage is this actually noticeable to the eye, rather than with instrumentation?