when engaged, the pcm should not be able to take over and upshift.....if you reach too high of a speed/rpm you should hear a loud chime, the pcm is supposed to limit your speed to protect the trans, but once again should not upshift for you....now it'll downshift for you when coming to a stop, but that's it....you can also start out in 2nd gear from a dead stop....and be able to throw it into Tap Shift even while driving, which is the only time it really can help say you want to downshift and take off....but with 4 gears the fun is limited....
