Ferguson was a good special teams player and acknowledged hard worker that never broke through to be a viable starter. He was ok as a 4th WR. Bush was much the same, excelled on ST but you didn't want him at CB except maybe as a dime back. I think a lot of the difference was that Ferguson was drafted in the 2nd round, and expected to become a starter, whereas Bush was a UDFA, so everything beyond a camp body was a bonus.