I enjoyed Foundation and Earth. Another reviewer pointed out that Asimov had written the series into a corner with nowhere to go. However, I would have enjoyed learning more about how the Galaxy evolved after "the decision".

That said, this book is an excellent prequel. Delving into Hari Seldon's first conception of Psychohistory and his initial time on Trantor. Going on the run from forces that want to control psychohistory he learns about the conditions on Trantor, history and different cultures that help him develop Psychohistory into a practical science.

The book also sheds light on events that happen in the previous books.