George Simmons' "Differential Equations with Applications and Historical Notes" vs. "Differential Equations: Theory, Technique, and Practice" I've heard much acclaim for George F. Simmons' "Differential Equations with Applications and Historical Notes" (2nd edition). I've noticed there's a newer book by Simmons and Krantz entitled "Differential Equations: Theory, Technique, and Practice". Is the latter a revision of the former or is it an essentially different book? How do they compare? Is the newer book as well written and as mathematically rigorous as the older one? Unfortunately Amazon don't provide a "Look Inside" for either book and my uni's library carries only the first of the two.
 A: From the MAA review of Differential Equations with Applications and Historical Notes:

Some years ago, an attempt was made to update Simmon’s book. The result was published as Differential Equations: Theory, Technique, and Practice, by Simmons and Steven Krantz. Alas, much of the charm of the original disappeared in the new version. So it is good news that CRC has brought back the original book in a third edition. I compared it to the second edition and decided that the changes are mostly minor additions dealing with topics Simmons enjoys. Most importantly, the author’s unique personality shines through.

From the MAA review of Differential Equations: Theory, Technique, and Practice:

Differential Equations: Theory, Technique and Practice is an introductory text in differential equations appropriate for students who have studied calculus. It is based on George Simmons' classic text Differential Equations with Applications and Historical Notes. The preface says that this revised version brings the older text up to date and adds some more timely material while streamlining the exposition in places and augmenting other parts.
While this is a more than adequate introductory book on differential equations, it is rather a disappointment—especially given its heritage. I say this knowing that the revised text is, in several places, pedagogically superior to the original book. Nonetheless, Simmons' classic text has a kind of charm that is still apparent 34 years after its original publication. Its pervading sense of reverence for scholarship and respect for work of past masters were uncommon when the book first appeared and are now rare indeed. Some of Simmons' touch remains, but it seems woefully diluted.

For more (opinionated) information on the similarities and differences, I think you will find the full text of the second review to be helpful.
Clarification: The first review is of Differential Equations with Applications and Historical Notes. The book has three editions. It seems that the second edition added a lot but the third edition didn't add that much. The third edition was published in 2018, so it is clear that this book has not been abandoned, despite the release of the second book in 2007. The second review is of Differential Equations: Theory, Technique and Practice, which is a different book. This book is not another edition of the first one; it is a different book based on the first one, sharing one of the authors. The opinion of the reviews in general is that the first book is charming and but conflicts with modern ideas about what should be taught in Differential Equations (see this article for some of the criticisms levied against the traditional style; in general the older style stresses finding analytic solutions and the new style stresses qualitative and numerical methods). The second book is a bit more in line with the newer style, but the reviewers complain that it has lost the charm of the first one. Ultimately, which book is the "best" is an opinion. Personally, I am going to read the first book because it seems more fun, but it is important to keep in mind that in the  "real world," some of the more specific methods to find analytic solutions (such as integrating factors) don't see much use.
