I have both watches..... and as ZTech said, if you need to dress up every once in a while, take the PO which is pretty much like a Submariner - it fits for every occasion. It is one of the very few chronos that can be used under water (the gen, that is) and it is a great watch.
The Oris is also a quality piece and I love my CC but that watch is more on the surfer side of life. It does not fit under a cuff and it looks kinda stupid with a suit.
The PO can be put on a leather strap easily, the Oris needs custom made straps. The original rubber strap cannot easily be changed in size (like a standard leather strap) someting that bothers me in summer because when its hot, I like my wristbands wider...
At the end of the day, you need to decide. Either way, you can't really go wrong...