Well I tried them both on and I thoroughly didn't like the Oris but totally adored the PO, which is bad news for my wallet! The Oris is too chunky looking and I didn't like the polished strap. Also the face is actuall uglier than in the photo.
I almost bought the PO but they only offered a derisory £150 off the RRP (7.5%) for which I almost wet my pants and told them to go whistle (this was Goldsmiths so perhaps no surprise). Anyway I'm going to hunt round for some smaller independent dealers in the hope of finding a better discount, but the good news is I have found my watch.
P.S. - maybe I should go second hand?