I am the writer of post in question. I have got my fair share of working on different technologies and different architectures.
Based on above, I can safely say that having Service layer and DAO layer is always a good idea.
DAO should be limited to only remove/update/insert/select Entity objects into/from database and that's all. If you want to do anything extra in terms of logic, add it to Service layer. This will help in making code modular and easily replaceable when database is replaced (for some part of data). This is specially applicable in applications involving reports which have heavy logics even after fetching data from database.
Also, in Spring, security is applied at service layer ideally. You would not like to change this way.
