Struts 2 OGNL s:iterator vs JSTL c:forEach performance

Question

I've been building some fairly dynamic web applications recently that rely heavily on database(JPA) backed configurations. These applications are multi-user, multi-account systems in which the end users can create custom forms based on JPA entities.

I noticed as my JSP pages became more complex that my performance and load times were taking a hit. Originally I had thought it was the data layer causing my bottleneck, but on a whim today I replaced a couple include pages which are created on the fly using lists of objects that are iterated over by struts with a JSTL based iteration scheme. I was blown away that my page load time went from about 10 seconds to around a second. The render times of the JSP pages increase substantially (with struts2 OGNL iteration) as the list sizes grow.

In my struts configs I have dev mode turned off and I'm using a simple theme set, nothing special. I'm considering rewriting some of my iteration heavy pages to use JSTL instead of struts, but I thought I would ask around to see if I'm missing something or if anyone has run into similar circumstances.