I am not sure, that my memory is correct, but it cannot be all that wrong.
Once upon a time, I was taught the Strathspey Poussette with three
diagonals. I suppose, that it was in 1960 or 1961. I was at Summerschool
59.60,61. Later I was taught two diagonals,but I must say, that I have no
memories of being taught the "old way".
I like the "old way", but I can see the advantages of the "new way".
1. The fact, that the steps in the "old way" can be of even length does not
appeal to me. I always teach the class to adapt the length of the step to
the formation for better phrasing and covering, but also to bring "light and
shade" in your dancing
2. For some people the diagonals spoil the formation. Well, maybe not for
everybody. The diagonals are very visible and give unexperienced dancers a
lot of help. I get better results, when teaching with two diagonals (NOT
3. In some dances we have a half poussette emerging from a wheel or a circle
(Lea Rig, Staffin Harvest).It is very easy and also elegant to make a
diagonal there. It would probably be rather awkward to try to start the
half poussette from the middle.
Conclusion: Both ways have their merits. Unfortunately they do not mix well,
so I vote for the "new way". Happy Dancing, Frans Ligtmans.