Before getting started I had better list the versions and books I mention. (I do this so that anyone who knows more than I can see where I am coming from. The details are just there to be specific - they do not indicate any particular difference from any other date of the edition.)
"pre-anniversary" 1916
This is the edition published in 1918. My book has a "Copyright, 1918. By the Gregg Publishing Company.
The preface by John Robert Gregg is dated "New York, June 17, 1916" (I wish it said who wrote the outlines.)
Anniversary
My copy is a British version. Copyright, 1930. (Again I wish it said who wrote the beautiful outlines.)
Simplified 1960
2nd Edition.
Copyright 1960 McGraw-Hill Publishing Company Limited. Printed in Great Britain. John Robert Gregg,
Louis A. Leslie, Charles E. Zoubek, Ernest W. Crockett. Again William C. Blackwell wrote the outlines.
My copy was reprinted in 1974 and was the one I (originally) learnt from.
Simplified Third Edition
Gerard O'Kennedy
Copyright 1991 McGraw-Hill Book Company
"The present edition, adapted to suite Irish and United Kingdom conditions and requirements,
retains the popular innovations introduced by the Simplified Manual and also incorporates
many of the changes in the Gregg shorthand diamond jubilee series and in Gregg Shorthand Series 90."
I would guess that Gerard O'Kennedy wrote the outlines himself.
So which Gregg shorthand version would I choose?
I first learnt (learnt but incompletely, so that I was not proficient in it -- though I could write all I needed, albeit a little inconsistently) the simplified version. I learnt it from the second edition. However I was annoyed by its rather patronising tone, its definition of English words and its constant banging on about commas. The point of a shorthand book is to teach shorthand, not English. (But I can understand why. For in those recent days of the 1960s education was beginning to go downhill in regards of the correctness of English so that secretaries, who needed to use English, needed more than the common amount of teaching in order to use good English. -- It is plain to see that this book is definitely aimed at potential secretaries.) The book has an emphasis on British English rather than American English which makes it more friendly. I was just very lucky that when I picked a book from the shelves to learn Gregg shorthand this was the one that was there.
Compared to the original 1950 Simplified English edition it is identical in what it teaches. Lesson for lesson, what it expounds is the same. The 1950 edition is a beautiful book in the same format as all the anniversary books and the pre-anniversary manual. It has an approach in what it teaches similar to the anniversary one. The 1950 has, generally, more reading material. The 1960 has more explanations. At the end of chapters are writing exercises which give useful guidance on keeping the writing of outlines neat and distinct; it also has timings for its reading exercises so that you are encouraged by how you are getting on. The 1960 also introduces things more discretely. For example in lesson 21 whereas the 1950 introduces the n-t & n-d blends in one paragraph with a following block of outlines showing them all, the 1960 has one paragraph for n-t followed by examples, and one paragraph for n-d followed by examples. A minor point, but to someone picking it up alone and for the first time it is more helpful.
In the final three lessons of both no new principles are given. The 1950 has vocabulary lists of shorthand forms before the reading exercises but the 19560 does not though not much is lost in this.
So overall the second edition holds your hand more. For self teaching it is more helpful. So if you can stand being patronised a little (though along with that it gives some inspiration and goals) I would advise that over the original 1950 edition.
Both the 1950 and 1960 have beautifully written outlines by William C. Blackwell. Just a beautiful as the anniversary and pre-anniversary manuals and books.
I am not sure how my 1950 edition differs from the American one. It states "adapted to suit British conditions and requirements" and I can see British towns listed at the end, but I hope nothing of note is different. I presume the 1960 edition is similarly similar.
But.
Between the American and British third editions there must be some differences - that is if there was
ever a third edition known in America. For, as mentioned in the edition descriptions at the start,
it is Simplified plus an amalgam of series 90, diamond jubilee editions. I suspect that in America
only diamond jubilee and series 90 are known.
This third edition is most unattractive to read. The outlines are rather jagged and misshapen.
So whereas I constantly read in all my anniversary books that reading good shorthand fixes
the outlines in mind and is a good way to help good writing, these third edition forms do not do that.
My heart sinks when I look at it.
(I am also a bit suspicious of what this third edition espouses for it says "Good stenographers are
always in demand." Now I think that in the 1990s dictaphones had really come to the fore and so
shorthand in a secretary was distinctly on the wane.
I therefore reject anything beyond the second edition (for which, as for anniversary, an excellent
Functional Method book by Leslie is available).
So, I learnt the simplified version. While doing so I sought occasional advice from an aunt (I say aunt, but she was just a school friend of my mother's) who learnt the anniversary edition (then the latest available) before becoming a secretary. She introduced me to one or two extra brief forms saying that they saved an awful lot of time, and also the shorter way of representing r.
After a long break I decided to refresh my knowledge of shorthand by starting from scratch with the "much better" anniversary edition. Armed with the manual (one can really appreciate why the arrival of this book was welcomed by shorthand teacher as easing their teaching methods) I began. There is so much material around concerning anniversary shorthand that it is a delight to be part of it; the Leslie Functional Method is truly great.
I am not yet proficient in it and have lessons to complete. I do have my doubts about its practicality (for I will never achieve high speed). The brief forms do load the mind and are, to an irregular user, rather forgetable. Likewise the prefixes and suffixes.
Although I said that there are lots of prefixes and suffixes, it is always tempting when writing a word and recognising a suffix which, even if it only occasionally appears, is so much part of the word that you feel you ought to be using a short form for it.
Compared to the second edition, the third abandons 5 prefixes, but oddly has the re-appearance from Anniversary, of one: the strange aggr...
I am afraid I must resort to handwriting here. I need to illustrate with shorthand outlines, and I am not able to elegantly fix little pictures amongst the ascii text using this html stuff. This picture is rather rough. I will re-do it later.
It is difficult to be too dogmatic about this, for American English is pronounced differently to British English. The British grunting sound at the end of formER is pronounced with a distinct R drawl in America: f-or-m-rrrrr. In the Irish pronunciation this rrrrr is evident too. So it is no wonder that the Irish born Gregg who spent most time advancing the system in America should tend to this naturally and not be troubled by certain British differences.
The sound of R is a problem for nearly all shorthand systems based on pronunciation. Pitman is hardly better and has the drawback of two signs for the letter r.
Pronunciation generally
All pronunciations systems cannot be strict. For one thing, regional accents differ. Another is that how a language is spoken changes over time. Suppose a shorthand system had captured spoken English in Chaucer's time. It would very hard to read today. Another folly is people (such as George Bernard Shaw) who attempt spelling reform (sorry America - I know you tried this) in order to simplify things (e.g. change "thought" to "thort") for even these invented simplifications may only last a limited period of time (who is to know if "thort" may become "thot" in a hundred years?).
So all this diatribe over the letter r cannot be taken too far; everything is a compromise. Extreme cases cannot dictate to the general whole and its soundness. It is all a grey area.
Many of the abbreviating principles in the Anniversary edition ensure that the outlines do no go too far below (or above) the line. It makes the writing neater.
I omitted to give my answer to which system I would choose.
I would choose the system I originally started to learn. I would learn from the second edition of the simplified version. For, despite the absence of some prefixes/suffixes and brief forms, it has less oddities than Anniversary, less things to memorise, and a more consistent treatment of R. So it is much easier to get confidence in the whole system. This edition also helps you teach yourself if you start from nowhere.
But since I have embarked on Anniversary I will persist with that. It really feels good to have all those words at your fingertips (eventually!). I will also use one or two of the prefixes & suffixes from the pre-Anniversary book.