If most ones of your team are not familar with Struts and no available Tutor for it, you should not take Struts as frameworks.
As you have said, MasterCraft is good one for your team. Maybe you can have a research on Struts first but not using it in this project.
Pros:
1.Open source framework
2.Good example for understanding J2EE Design Pattern
3.Excellent Tag lib
4.Make application more configrurable
5.Supported by many tools & popular IDEs
Cons:
1.Still in development
2.Taglibs are hard to grasp
3.Add complexity to application
If your team uses XP as process, you can hava a spike on it first. And then applying Pair Programming to teach blue ones.
Hope that it can help u!
[ February 26, 2003: Message edited by: tonyqu ]