Well having travelled on RCI and Celebrity before we thought we'd try P&O.
Despite booking a year ago we were given very little choice of availability and selected two staterooms for our party of 4 on deck C. We said no to the auto upgrade as P&O would not guarantee that a linked booking would be treated as a priority and would be kept together (this really isn't fair if you are a family or party that wants to be near by)
As the time for our cruise approached, we noticed P&O started to heavily discount the sailing on 21 August 2012 with a number of "getaway deals". We therefore contacted Customer Service and after a bit of a faff we were upgraded the week before we sailed. Although both staterooms were on the same deck, the staterooms were spread - one mid and one forward. It was frustrating to see getaway fares offered that would have saved us almost £1000! Whether the new P&O Price Pledge will finally see early bookers treated fairly we will wait and see. You are advised to contact Customer Service and too be persistent with your query!