In your experience, what do you don’t like about Spring? Are there any pitfalls

Spring has become very huge and bulky. So, don’t over do it by using all its features because of the hype that Spring is good. Look at what parts of Spring really provides some benefits for your project and use those parts. In most cases, it is much better to use proven frameworks like Spring than create your own equivalent solution from a maintenance and applying the best practices perspective. For example, all spring templates (jdbc, rest, jpa etc.) have the following advantages — perform common setup routines for you, let you skip the boilerplate and concentrate on the logic you want.

Spring MVC is probably not the best Web framework. There are other alternatives like Struts 2, Wicket, and JSF.  Having said this, Spring integrates well with the other Web frameworks like Struts, JSF, etc.

The XML files can get bloated. This can be minimized by carefully considering other options like annotations, JavaConfig, and having separate XML configuration files.