We chose this cruise to get away from British winter weather and P&O happened to be offering the itinerary. Previously we have been with RCL so it was interesting to see the differences. The food was very good in the restaurants but the waiters seemed to be under a lot of pressure - almost the opposite of RCL; the in-house entertainment troop were excellent and the guest entertainers were mostly to our taste. We liked the little extra touches from P&O - the copy of the ship's log presented at the end of the cruise, the talk by the captain (and his high visibility during the voyage), the chocolates each night on our pillows, the copies of each evening's menu for us to keep and the free launderette. The fact that drinks were at normal pub prices and not extortionate (as on RCL) was also a pleasant surprise.
The ports were all worth visiting and the excursions that we took were reasonably priced. We found the sea day entertainment a bit limited though, unless you were interested in beauty treatments or deck sports (in the North Atlantic in February!!)
Although it had been refurbished in 2011 we thought the Oriana a little bit old-fashioned, but perhaps that reflects her target market.
On the whole, a very enjoyable cruise. It included a visit to Casablanca which was very interesting.