Well, I added Javatemplate plugin: http://struts.apache.org/2.x/docs/javatemplates-plugin.html
and now the page renders in about 3 seconds. That solves the immediate issue for me. Not sure what's going on with struts2 tags, but in the default configuration they seem to be hideously slow. Am I doing it wrong? Should I not be using struts tags in JSP pages?