Arrival/embarkation: We flew into Heathrow two days early in order to sightsee in London. We stayed at the moderately priced Comfort Inn Victoria which is located a block from Victoria's station. It has small clean rooms, nice continental breakfast included, within easy walking distance of Hop On, Hop Off bus stops, Victoria Station (if you choose to ride the Tube or trains), and Buckingham Palace.
Look for Pubs on your travels throughout the British Isles that serve food for good, reasonably priced meals.
We had purchased bus transfers from Heathrow to Southampton from Princess so we took a blacktop (metered) cab back to Heathrow, found the Princess reps in the arrival area and were quickly ushered to the bus. Our luggage was tagged and we didn't see it again until it was outside our cabin door about half an hour after our arrival onboard.