We worked all year on our vision system, and it worked pretty well. We did not use it during auto. We had a piezo buzzer attached to our operator's gamepad, which would sound whenever we were relatively close to a trailer we could score on, during Teleop. We also had a button on our pad that, if held, would automatically dump balls, if I had driven into a correct trailer and was locked on to it.
At nationals, it worked about 80% of the time, when it was sunny out.
-Nick