To get an idea whether its worth to use physX based collision for the sword fight think about what effect you want in case the sword hits a shield.
Do you want that the models react to it?
Do you want to switch to ragdoll physics in that moment?
Do you want a mix of animated and ragdoll controlled character?

http://www.puppenheim.org/
http://www.wuerfels-welt.de
Old Game Tutorial: http://www.puppenheim.org/MITutorial.zip
Free Game Editor: http://puppenheim.org/AlienalsWeihnachtsmann.zip
http://www.puppenheim.org/blender_starting_main_settings.txt