This was my first cruise ever. I decided to accompany my mother and sister as the price was reasonable. I have been somewhat of a skeptic of cruises, but after this experience I am somewhat of a convert.
The pre-cruise customer service was awful to put it mildly. We used a EU based distributor for the booking. In terms of flights and hotels they could only suggest Princess's offerings, which were more expensive than booking direct with no added benefits. Also, all the additional information they were able to provide I could find on Princess's website, which provides you only the very basics. After few days of researching the web myself I knew as much as our booking agent. Very quickly it became clear with three of us any shore excursion was cheaper / same price to book direct instead of using Princess's offering. Also, then you are in control of the itinerary, and can modify it as you go if needed.
You are expected to conclude all your pre-cruise check-in on the Medaillon app. I swear this is the worst app I have ever used. It kept on freezing, not showing all the information, burning battery and requiring multiple restarts of the phone. This was also the case on the ship when connected to the Medaillon net. I used it once to try to order lunch by the pool. After multiple restarts I finally managed to place the order, which was then delivered to a wrong place as the app showed the waiter I was sitting at a completely different section of the pool. I have a one year old Android phone, so this cannot be the problem. My sister has a few years old iPhone, and experienced exactly the same problems.