Setting up
Tomcat in IDEA 4.5 is as easy as going to Settings | IDE | Application Servers and Add Tomcat Server.
Creating servlets or JSPs is as simple as creating a Web module, then New | Servlet, or New | JSP depending on your context. You can also just as easily create filters.
I like Eclipse a lot, and it keeps getting better, but personally I don't find it at all intuitive. Admittedly it's not hard once someone shows you, or you figure it out yourself, but not intuitive. As always, YMMV.