Hi,
in JSF each JSP has its own controller java class, this means you don't have by default centeralized control over your projects (all JSPs together). as far as I know in struts there is a centeralized control over all the project.
I didn't use struts before, but I do use JSF and it ws sufficient to me, there is always a way to do what you want, so just get proffesional in one of them (struts or JSF) and you will not need the other one, they are both handling the same design pattern.
Hope this ansowers your question