y on a JSP page results in many lines of code on your JSP page, including trycatch blocks to catch naming and finding exceptions.
Using a standard JavaBean as an intermediary between the JSP page and EJB server cuts down on the amount of code needed to add to a JSP page, and promotes reuse. The JavaBean should be a simple wrapper around the EJB you are accessing.
If you use a standard JavaBean you could also use the jsp:useBean tag to setup EJB parameters, such as the server URL and server security parameters.
Custom tags are also an option. However, they require a lot more coding than a simple JavaBean wrapper. The point should be to rewrite as little code as possible while at the same time keeping the JSP scriptlet content as light as possible.