Well written, easy to read, with lots of code fragments which clarify textual descriptions, and with references to Design Pattern and JSR too.

In the "Part I: Core Spring" Spring Container xml-based configuration is detailed covered. The Java annotation-based configuration is well explained too, as well as how Spring supports AOP.

In the "Part II: Spring application essentials" I've appreciated how Spring's data persistence and transactions management are presented, not focused on a particular technology, but different solutions are compared: JdbcDaoSupport - Hibernate - JPA, and JDBC - Hibernate - JPA - JTA transaction manager.
Than Spring MVC, Spring Web Flow and Spring Security are explained with the "In Action" approach which, in my opinion, is focused on demonstrating hands-on how to use the tools in an effective way, avoiding common pitfalls.

In the "Part III: Integrating Spring" I've appreciated how Spring makes simple working with WS, JMS and JMX. The last chapters "Odds and ends" covers few small topics extremely useful. ( )