If the gun is performing as expected (100%), why do you feel there is a need to swap out the extractor? Leave it alone. You have nothing to gain by swapping it out.
If you want to play with the trigger that is a whole new story! You can drop the trigger pull weight by simply installing the new LWD 3.5 connector http://bit.ly/nHidAO
BTW: The brand new modified LWD 3.5 connectors will start shipping this week. These have been completely redesigned and feature the slickest finish I have ever seen!