Ok after searching the net a bit I found this info....is it correct?
The Chiefs Special and Bodyguard are the same except the hammer is shrouded on the bodyguard and it has a manual cocking button, both are SA or DA while the Centennial is DAO.
If that's correct guessing it all really just comes down to preference. If you want to shoot SA and DA you need to choose between bodyguard and chiefs, probably lean bodyguard if you are carrying. If you don't care about SA then the Centennial.
So I understand the functional differences in SA and DA, but why/when would I use one or the other?