I finally got the time to get Pathfinder working (hopefully we will be able to use it at BattleCry@WPI), and here is a demo video of our robot following a simple trajectory that is similar to what we will use to get over a defense and line up for our auto shot.
https://youtu.be/m4pbv1_FC5I
Also, I attached a picture of a web interface I wrote (using pynetworktables2js) that allows me to see how well the robot is following the trajectory and easily tune the parameters. (Also, disregard the weird looking data, I was working on a problem when I took the screenshot)