There's a very good pronunciation guide in each.  Pretty well the same throughout, apart from the option of pre-occlusion.

truru said:

Is the only difference between the three versions the orthography used? There aren't any differences in grammar/explanations etc between the schools/adults versions?

Which pronunciation is used?

By and large the only difference in terms of course content is the orthography. There is a bit of additional material in the section on plurals in the KS version.

The three pronunciation sections differ somewhat, because the orthographies reflect pronunciation in different ways. Both the SWF/M and the SWF/T fail to enable the reader to distinguish some sounds by the spelling.

The pronunciation guide for SWF/T was written first; the SWF/M was based upon that. The KS version began with the SWF/T text but is greatly expanded and gives phonetic respellings.

These books use RMC pronunciation because that is what the author uses, but there is a mention of pre-occlusion in all of them, and more detail given in the KS version about the dialect differences than in the other two.

MAGA didn't – they only depicted the cover of the SWF/K coursebook.  As they decided to discriminate, let me tell people on this forum that there is a SWF/T coursebook (same cover, but with green background); and a KS coursebook (same cover – blue background).  The course has the same structure in all three.  All three have the same retail price £8.95.  MAGA doesn't seem to want you to have a choice which rather makes a mockery of the SWF agreement.  On the other hand, we have catered for choice (you haven't often heard that in the history of the Revival, especially the last 25 years of it).