Ahhh, a man in the know. I, too have a 4506; my brother raved so much, I had to bite. To me, the gun is flawless EXCEPT for its Tiger tank-like weight.
NM State Police carried them for years. Of course, the chances of having to make a water rescue is rare here, so they were safe.
Had a Smith 4586 which was the DAO version, had a lot going for it, but alas I could not shoot it well. Moved over to Sig P220s.