No obvious difference in performance when you are referring to
JavaBeans on Application Server (Assume your bean class do not look like serveral Mega bytes.)
When you are refering to Data Access Object in EJB 2.0 and the dao is huge in size, there can obvious drop in performance. For the dao with a lot of setter and getter and attributes, it is called fine-grained. It will create more network load if you always use lots of fine-grained dao.
The opposite of fine-grained is called coarse-grained.