Recently I was talking with an old friend (who is an active amateur operator) and my interest in ultralight DXing came up. He was keen on this and to him it sounds like a very interesting hobby and a possible extension of this SOTA activities.
What he asked and this got me thinking is what do we (as a hobby) consider rare DX? In the amateur radio world, this can be defined easily by various countries being less / non active on the air or the use of various modes / power levels (QRP). For somebody to say X is rare DX, what criteria can we use? Do we allow for things like stations being off the air which then allows another station to be heard in their place? What about those areas without / limited MW broadcasters, do you consider this is an advantage to those DX'ers?
I don't have the answers, just a mind that does not stop thinking.