Can't comment on the pro model or the Xtra wood, but can highly recommend the 686 onyx models.
I shoot the white onyx sporting and it has performed flawlessly in the field for doves and pheasants and swings nice for clays. It has been totally reliable in all sorts of conditions and has a great rep.
I have never personally handled the pro model, but from what I have read, it appears to be a "plain-jane" working version of a very classy and reliable action.
